DEPARTMENT OF HEALTH AND HUMAN SERVICES 

CENTERS FOR DISEASE CONTROL AND PREVENTION 

Advisory Committee on 

Immunization Practices (ACIP)

Summary Report

June 24, 2020 

Atlanta, Georgia 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

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Table of Contents Page

Agenda 3 

Acronyms 4-8 

Welcome and Introductions 9-11

Meningococcal Vaccines

 Introduction

 Safety and Immunogenicity of MenQuadfiTM

 MenACWT-TT (MenQuadfiTM): EtR, GRADE, and Work Group Considerations

 VFC Resolution Update: Meningococcal Vaccines

 VFC Vote

12-26

Influenza Vaccines

 Introduction

 Work Group Considerations and Proposed Recommendations

 Vote 

26-35

Coronavirus Disease 2019 (COVID-19)

 Overview of COVID-19 Disease

 SARS-CoV-2 Immunology

 US COVID-19 Epidemiology

 Routine Pediatric and Influenza Vaccination in the Setting of COVID-19

36-56

COVID-19 Vaccines

 Introduction

 COVID-19 Vaccine Development

 Landscape of Candidate COVID-19 Vaccines

 COVID-19 Vaccine Prioritization Considerations

 Work Group Considerations and Next Steps

57-82

Agency Updates

 Centers for Disease Control and Prevention (CDC) 82-83

Vaccine Supply Update 83

Certification 84

Membership Roster 85-94
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Acronyms

AAFP American Academy of Family Physicians 

AAP American Academy of Pediatrics

ACHA American College Health Association 

ACIP Advisory Committee on Immunization Practices

ACOG American College of Obstetricians and Gynecologists

ACP American College of Physicians 

AE Adverse Event

AFM Acute Flaccid Myelitis 

AGS American Geriatrics Society

AHIP America’s Health Insurance Plans

AI/AN American Indian/Alaskan Native 

aIIV Adjuvanted Inactivated Influenza Vaccine

AIM Association of Immunization Managers 

AIRA American Immunization Registry Association 

AMA American Medical Association

ANA American Nurses Association

AOA American Osteopathic Association 

APhA American Pharmacists Association 

APHL Association of Public Health Laboratories 

ASH Assistant Secretary for Health 

ASPR Assistant Secretary for Preparedness and Response 

ASTHO Association of State and Territorial Health Officers 

BARDA Biomedical Advanced Research and Development Authority

BLA Biologics License Application

BMI Body Mass Index

BSL-4 Biosafety Level 4 

CBER Center for Biologics Evaluation and Research 

ccIIV Cell Culture-Based Inactivated Influenza Vaccine

CDC Centers for Disease Control and Prevention

CHC Community Health Center 

CICP Countermeasures Injury Compensation Program 

CISA Clinical Immunization Safety Assessment 

CMIA Chemiluminescent Microparticle Immunoassay 

CMS Centers for Medicare and Medicaid Services

COI Conflict of Interest 

COVID-19 Coronavirus Disease 2019 

COVID-NET COVID-19-Associated Hospitalization Network 

CSF Cerebrospinal Fluid

CSTE Council of State and Territorial Epidemiologists 

Ct Cycle Threshold

CTN Clinical Trials Network 

DM Diabetes Mellitus 

DNA Deoxyribonucleic Acid 
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DoD Department of Defense

DSMB Data Safety Monitoring Board 

DTaP Diphtheria and Tetanus Toxoid and Pertussis 

DVA Department of Veterans Affairs

DVD Division of Viral Diseases 

ECMO Extracorporeal Membrane Oxygenation 

ED Emergency Department

EIP Emerging Infections Program 

EIS Epidemic Intelligence Service

ELISA Enzyme-Linked Immunosorbent Assay 

EtR Evidence to Recommendation 

EUA Emergency Use Authorization 

EV Enteroviruses 

FDA Food and Drug Administration

FHA Filamentous Haemagglutinin

FQHC Federally Qualified Health Center 

FY Fiscal Year 

GAVI Global Alliance for Vaccines and Immunisation; The Vaccine Alliance

GI Gastrointestinal 

GMC Geometric Mean Concentration

GMT Geometric Mean Titers 

GRADE Grading of Recommendation Assessment, Development and Evaluation 

HAN Health Alert Network 

HCoVs Human Coronaviruses 

HCP Healthcare Personnel / Providers

HCW Healthcare Workers 

HD-IIV High-Dose Inactivated Influenza Vaccine

HHS (Department of) Health and Human Services

HI Hemagglutinin Inhibition 

Hib Haemophilus Influenzae Type B

HIV Human Immunodeficiency Virus 

HPV Human Papillomavirus

HRSA Health Resources and Services Administration 

ICD International Classification of Diseases 

ICU Intensive Care Unit

ID Intradermal

IDSA Infectious Disease Society of America 

Ig Immunoglobulin

IHS Indian Health Service 

IIS Immunization Information Systems 

IIV Inactivated Influenza Vaccine 

ILI Influenza-Like Illness 

ILINet Influenza-like Illness Surveillance Network 

IM Intramuscular 

IMD Invasive Meningococcal Disease 
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IQIP Immunization Quality Improvement for Providers 

ISD Immunization Services Division 

ISO Immunization Safety Office

IVIG Intravenous Immunoglobulin 

LAIV Live Attenuated Influenza Vaccine

LRN Laboratory Response Network 

MASO Management Analysis and Services Office 

MedDRA Medical Dictionary for Regulatory Activities 

MERS Middle East Respiratory Syndrome

MIS-C Multisystem Inflammatory Syndrome in Children 

MMR Measles, Mumps, and Rubella 

MMWR Morbidity and Mortality Weekly Report

mRNA Messenger Ribonucleic Acid

NACCHO National Association of County and City Health Officials 

NACHC National Association of Community Health Centers 

NACI National Advisory Committee on Immunization Canada

NAPNAP National Association of Pediatric Nurse Practitioners 

NAS National Academy of Sciences 

NCEZID National Center for Emerging and Zoonotic Infectious Diseases 

NCHHSTP National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention 

NCHS National Center of Health Statistics 

NCIRD National Center for Immunization and Respiratory Diseases 

NEJM New England Journal of Medicine

NFID National Foundation for Infectious Diseases 

NHIS National Health Interview Survey 

NHSN National Healthcare Safety Network

NIAID National Institute of Allergy and Infectious Diseases 

NIH National Institutes of Health

NIP National Immunization Program 

NMA National Medical Association 

NNDSS National Notifiable Diseases Surveillance System 

NSSP National Syndromic Surveillance Program 

NVSN New Vaccine Surveillance Network 

NVAC National Vaccine Advisory Committee 

NVPO National Vaccine Program Office 

NVSN New Vaccine Surveillance Network 

NYC New York City

OASH Office of the Assistant Secretary for Health 

OID Office of Infectious Disease 

OIDP Office of Infectious Disease Policy and HIV/AIDS 

OSHA Occupational Safety and Health Administration 

PCP Primary Care Practitioner

PCR Polymerase Chain Reaction 

PCV Pneumococcal Conjugate Vaccine

PEP Post-Exposure Prophylaxis
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PHAC Public Health Agency Canada 

PhRMA® Pharmaceutical Research and Manufacturers of America®

PICO Population, Intervention, Comparison, Outcomes 

PIDS Pediatric Infectious Disease Society 

PIMS Pediatric Inflammatory Multisystem Syndrome 

PPE Personal Protective Equipment 

PPV Positive Predictive Value 

PRAMS Pregnancy Risk Assessment and Monitoring System 

PrEP Pre-Exposure Prophylaxis 

PRNT Plaque Reduction Neutralization Test 

PT Pertussis Toxin

PT Preferred Terms (MedDRA)

QIV Quadrivalent Influenza Vaccine 

RCT Randomized Controlled Trial

RCA Rapid Cycle Analysis

RIV Recombinant Influenza Vaccine 

RN Registered Nurse

RNA Ribonucleic Acid 

RR Relative Risk

rRT-PCR Real-Time Reverse Transcription Polymerase Chain Reaction 

RSV Respiratory Syncytial Virus 

RT-PCR Reverse Transcriptase Polymerase Chain Reaction

SAE Serious Adverse Event 

SAHM Society for Adolescent Health and Medicine 

SARS Severe Acute Respiratory Syndrome 

SARS-CoV-2 Severe Acute Respiratory Syndrome Coronavirus 2 

SCR Seroconversion Rate

SD-IIV3 Standard Dose Inactivated Influenza Vaccine

SDOH Social Determinants of Health 

SET-NET Surveillance for Emerging Threats to Mothers and Babies Network 

SHEA Society for Healthcare Epidemiology of America 

SME Subject Matter Expert

SNS Strategic National Stockpile

STEMI ST-Elevation Myocardial Infarction 

TB Tuberculosis

Tdap Tetanus Toxoid, Reduced Diphtheria Toxoid, and Acellular Pertussis

TEC Tribal Epidemiology Center 

TIV Trivalent Influenza Vaccine

UK United Kingdom

UNICEF United Nations Children’s Fund 

US United States

US Flu VE US Influenza Vaccine Effectiveness Network

USG US Government 

USPHS US Public Health Service 

VA (US Department of) Veteran’s Affairs 
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VAERS Vaccine Adverse Event Reporting System

VE Vaccine Efficacy

VE Vaccine Effectiveness

VFC Vaccines For Children

VICP Vaccine Injury Compensation Program 

VIS Vaccine Information Statement 

VRBPAC Vaccines and Related Biological Products Advisory Committee Meeting 

VRC Vaccine Research Center (NIAID)

VSD Vaccine Safety Datalink

WG Work Group

WHO World Health Organization

WRA Women of Reproductive Age 
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Call To Order, Welcome, Overview, Announcements, & Introductions

José Romero, MD, FAAP

ACIP Chair

Amanda Cohn, MD

Executive Secretary, ACIP / CDC

Dr. Cohn called to order the June 2020 Advisory Committee on Immunization Practices (ACIP), 

welcomed those present, and provided instructions for the various platforms through which 

participants were joining the meeting (e.g., Zoom, webinar, teleconference). She announced 

that 2 additional virtual ACIP meetings dates have been added: August 12, 2020 and 

September 16, 2020. These dates are subject to change. Any changes made will be updated on 

the ACIP website and sent via email to all subscribers to the ACIP/CDC page. The next 

regularly scheduled meeting is October 28-29, 2020. At this time, it is not known whether the 

October meeting will be virtual or in person. 

She noted that slides to be presented during this meeting were made available through a 

ShareFile link for liaison and ex-officio members and for members of the public on the ACIP 

website at the following URL, which eventually will be replaced with a 508-compliant version: 

https://www.cdc.gov/vaccines/acip/meetings/slides-2020-06.html

Slides presented during this meeting will be posted on the ACIP website approximately 4 weeks 

after the meeting. The live webcast videos also will be posted in about 4 weeks following the 

meeting, and the meeting minutes are posted to the ACIP website generally within about 120 

days following the meeting. Minutes from the February 2020 meeting were scheduled to be 

posted shortly.

Dr. Cohn emphasized that ACIP is, at its heart, a public body. Engagement with the public and 

transparency in ACIP’s processes is vital to the Committee’s work. She recognized that the 

virtual environment makes this especially challenging and noted that while there would be an 

opportunity for public comment during this meeting, they do miss seeing everyone in-person 

and being able to interact and connect in that way. As part of ACIP’s commitment to continuous 

improvement, ACIP has strengthened its oral and written public comment process to 

accommodate increased public interest in ACIP’s work, maximize opportunities for comment, 

and make public comment more transparent and efficient. She announced that for this meeting, 

one oral public comment period would be held during the first afternoon at approximately 11:25 

AM, prior to lunch. 

Call To Order, Welcome, Overview, Announcements, & Introductions 
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To create a fair and efficient process for requesting to make an oral comment, people interested 

in making an oral comment were asked to submit a request online in advance of the meeting.

Priority is given to these advance requests, and if more people request to speak than can be 

accommodated, a blind lottery is conducted to determine who will be the speakers. Speakers 

selected in the lottery for this meeting were notified in advance of the meeting. Written public 

comments may be made via regulations.gov using the docket number ID CDC-2020-0049. 

Information on the written public comment process, including information about how to make a 

public comment, can be found on the ACIP website. Regulations.gov closes approximately 24 

hours following the end of the ACIP meeting. Dr. Cohn pointed out that written public comments 

could be made during and after the meeting as well.

As noted in the ACIP Policies and Procedures manual, members of the ACIP agree to forgo 

participation in certain activities related to vaccines during their tenure on the committee. For 

certain other interests that potentially enhance a member’s expertise while serving on the 

committee, CDC has issued limited conflict of interest (COI) waivers. Members who conduct 

vaccine clinical trials or serve on data safety monitoring boards (DSMBs) may present to the 

committee on matters related to these vaccines, but are prohibited from participating in 

committee votes on issues related to those vaccines. Regarding other vaccines of the 

concerned company, a member may participate in discussions with the provision that he/she 

abstains on all votes related to the vaccines of that company. At the beginning of each meeting 

and prior to each vote, ACIP members will state any COIs.

Dr. Cohn indicated that detailed instructions for submission of names of potential candidates to 

serve as ACIP members is now available on the ACIP website. Applications for ACIP 

membership are due no later than July 1, 2020 for the 4-year term beginning July 1, 2021. 

Dr. Romero welcomed everyone to the June 2020 virtual meeting of ACIP. He conducted a roll 

call of ACIP members, during which no members declared any COIs. He then requested that 

the Liaison and Ex Officio members introduce themselves. A list of Members, Ex Officio

Members, and Liaison Representatives is included in the appendixes at the end of the full 

minutes from the June 2020 ACIP meeting.

NCIRD Director’s Welcoming Remarks

Nancy Messonnier, MD, Director

National Center for Immunization and Respiratory Diseases (NCIRD)

Centers for Disease Control and Prevention (CDC)

Good morning, everybody. Thank you for joining us at our first virtual ACIP meeting. I’d like to 

thank the ACIP members, the ex officio members, the liaisons, and the rest of the audience who 

is listening to us today. I’d especially like to thank the CDC team, both our regular ACIP team 

and all of the folks who are supporting us today. I know this won’t go off without hiccups, but we 

certainly appreciate the village that it takes to pull off this kind of meeting.
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Before we get started today, I’d like to take a moment to speak to you about the events that are 

taking place in our country. Over the last few months, we’ve been battling a pandemic, its 

economic consequences, and the painful reality of racial injustices and inequities. Like many of 

you, I feel overwhelmed by these circumstances. However, we cannot ignore the racial injustice, 

systemic racism, and their impact on the longstanding racial disparities in healthcare and public 

health in the United States (US). The lack of diversity in organizations across multiple sectors, 

including scientific and medical pursuits, is mirrored in our healthcare system where significant 

health disparities exist in certain communities.

COVID-19 is just the latest in a long list of diseases that underscore the health inequities in the 

African American community. In order to close the health disparity gap, there is much more that 

needs to be considered when designing and implementing our public health work. There is also 

much more to do within our own organizations to increase diversity and provide more 

opportunity for our peers who are Black, Hispanic, and from other racial and ethnic minority 

groups. It is important to mentor, recruit, and retain the next generation of scientific leaders who 

reflect the communities we serve, especially in and from the communities who bear the burden 

of many health inequities.

At NCIRD, we are working through programs like the Morehouse College IMHOTEP program to 

build the pipeline of racial and ethnic minority candidates for our flagship programs like 

Epidemic Intelligence Service (EIS) and we are committed to improving our workplace diversity 

and inclusiveness so that all staff feel welcomed, fully engaged, and supported. We must also 

develop, enhance, and maintain strong partnerships, which are vital in implementing our public 

health programs. We are continuing funded partnerships with groups like the National 

Association of Community Health Centers (NACHC), and we’re strengthening existing 

partnerships through improved connections between state immunization programs and state 

Health Equity Directors.

I want to close by saying how much I appreciate the dedication and perseverance of our CDC 

staff and our many partners who continue the critical daily work of protecting people and saving 

lives despite the extreme turbulence and uncertainty right now. We are a country founded on 

the ideals of opportunity and equality and as physicians, scientists, and public health 

professionals, we have a real responsibility to live up to those values. Let’s double down on our 

commitment to improve health outcomes for all people. I challenge everyone in the vaccine 

space to listen, create opportunities for open and honest dialogue, and to do your part to 

support, recruit, and retain the most diverse workforce possible—especially in our scientific 

leadership positions. While the events happening in our country are extremely painful, they are 

a signal to those of us in leadership positions to chart a better path forward starting now. Thank 

you.
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Introduction

Veronica McNally, JD

Chair, Meningococcal Work Group

Advisory Committee on Immunization Practices

President and CEO, Franny Strong Foundation

Ms. McNally introduced the Meningococcal Vaccine WG session. A new meningococcal 

serogroup A, C, W, Y (MenACWY) vaccine, MenACWY-TT (MenQuadfiTM), was approved by the 

Food and Drug Administration (FDA) in April 2020. It is approved for individuals ages ≥2 years.

The issue under consideration is whether MenACWY-TT should be available as an option for 

MenACWY vaccination according to currently recommended dosing and schedules in the 

Vaccines for Children (VFC) program. The VFC vote will address whether MenACWY-TT should 

be included as an option for meningococcal serogroup A, C, W, and Y vaccination in the VFC 

program using currently recommended dosing and schedules for MenACWY vaccines. No ACIP 

vote is needed as no changes to recommendations are proposed.

Meningococcal disease is a serious infection that can progress rapidly. One in 10 patients die 

despite antibiotic treatment. Among survivors, 1 in 5 have long-term sequelae that can include 

hearing loss, amputation, and cognitive deficits. The incidence of meningococcal disease is at 

an all-time low in the United States (US) with 0.10 cases per 100,000 population in 2018. 

Serogroups C, W, and Y combined currently account for approximately 50% of all cases.

MenACWY vaccines have been recommended for adolescents and persons at increased risk 

since 2005. Three MenACWY conjugate vaccines are currently licensed:

 MenACWY-D (Menactra®) 

 MenACWY-CRM (Menveo®) 

 MenACWY-TT (MenQuadfiTM) 

The populations currently recommended for MenACWY vaccination are adolescents with one 

dose at 11 or 12 years of age and a booster at age 16 years, and persons aged ≥2 months at 

increased risk for meningococcal disease due to specified underlying conditions or exposures.

The Meningococcal Vaccines WG reviewed data on MenACWY-TT safety, immunogenicity, 

persistence of immune response, and concomitant administration with other vaccines. The WG 

used Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) 

along with the Evidence to Recommendations Framework (EtR) to assess the use of 

MenACWY-TT as an option for MenACWY vaccination.

Meningococcal Vaccines
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The agenda for this session included presentations on the following topics:

 Safety and Immunogenicity of MenQuadfiTM

 MenACWY-TT (MenQuadfiTM): EtR, GRADE, and WG Considerations

 VFC Resolution Language

Safety and immunogenicity of MenQuadfiTM 

Meningococcal (Groups A, C, Y, W) Conjugate Vaccine

Dr. Corey Robertson

Sanofi Pasteur

Dr. Robertson provided information regarding Sanofi Pasteur’s newest MenACWY vaccine, 

MenQuadfiTM. Invasive meningococcal disease (IMD) still poses a public health challenge given 

its high case fatality rate of approximately 10% to 15%. About one in five survivors are left with 

serious permanent sequelae3,4. Thankfully, MenACWY vaccines have been effective at 

preventing the disease. Since introduction of the first MenACWY conjugate vaccine (Menactra®) 

in 2005 followed by Menveo® in 2010, IMD caused by serogroups C, W, and Y has declined by 

more than 90% among adolescents and young adults5

. There is still room for improvement with 

MenACWY vaccination, including an opportunity to expand protection at both ends of the age 

spectrum with a single vaccine. With this in mind, MenQuadfiTM has been developed. 

[References: 1. Thompson MJ, et al. Lancet. 2006;367(9508):397-403. 2. WHO. 

https://www.who.int/en/news-room/fact-sheets/detail/meningococcal-meningitis accessed March 

2020]. 3. CDC. MMWR. 2013;62(RR-2):1-22. 4. Rosenstein NE, et al. N Engl J Med. 

2001;344(18):1378-1388. 5. MacNeil JR, et al. Clin Infect Dis 2018; 66:1276–81].

MenQuadfiTM is a quadrivalent meningococcal conjugate vaccine intended to help prevent IMD 

caused by serogroups A, C, W, and Y. In April 2020, FDA approved the vaccine for use in 

persons 2 years of age and older. This includes adults 56 years of age and older, a segment of 

the US population for whom no licensed meningococcal conjugate vaccine existed. 

MenQuadfiTM was developed with the ambition of being used across a broad age range. Sanofi 

Pasteur is currently conducting ongoing trials to assess the performance of MenQuadfiTM in 

children as young as 6 weeks of age. In those same studies, Sanofi Pasteur is examining 

different dosing intervals with the hope of it being incorporated in various immunization 

schedules that exist worldwide. MenQuadfiTM contains tetanus toxoid as a protein carrier. Each 

0.5-mL intramuscular (IM) dose contains 10 μg each of the 4 meningococcal polysaccharide 

antigens contained in the vaccine. MenQuadfiTM will be supplied in a single dose vial as a fully 

liquid formulation or solution that does not require reconstitution.

Dr. Robertson reviewed the clinical trials that comprised the development program that led to 

the initial licensure of the vaccine in the US, which are shown in this table:
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In the first 3 trials, MenQuadfiTM was evaluated in adolescents, older adults, and as a booster. In 

the last 2 trials, MenQuadfiTM was evaluated in children 2 through 9 years of age and persons 

10 to 55 years of age. The comparators used are shown in the 4th column of the table. All trials 

were randomized, blinded, and active-controlled. Due to randomization, demographic 

characteristics were well-balanced across vaccine groups within each of the trials. The study 

populations for each trial reflected the racial and ethnic diversity of the US population to varying 

degrees. The results of 4 of the 5 trials have been published in the medical literature, while the 

manuscript for the remaining trial is currently under review. Dr. Robertson described each study.

MET50 was a study of 1700 adolescents 10 through 17 years of age who were randomly 

assigned to 1 of 4 vaccine groups. Group 1 received MenQuadfiTM (N=503), Group 2 received 

the comparator MenACWY-CRM (N=501), Group 3 received MenQuadfiTM+Tdap+HPV (N=392), 

and Group 4 received concomitant Tdap+HPV (N=296) without MenQuadfiTM. The mean age of 

the study population was just over 11 years. In terms of safety, the frequency of solicited 

reactions was similar across the different vaccine groups, except for myalgia that occurred at a 

higher frequency in the concomitant vaccination groups that included Tdap and human 

papillomavirus (HPV).

Turning to immunogenicity, MenQuadfiTM induced seroresponse rates that were non-inferior to 

the comparator vaccines. Point estimates were consistently higher for MenQuadfiTM than for the 

comparator across the different vaccine serogroups, and the 95% confidence intervals were not 

overlapping. The same pattern was seen with respect to seroprotection rates and postvaccination geometric mean titers (GMTs), including a pronounced response to serogroup C 

relative to the comparator vaccine. Concomitant administration of Tdap and HPV did not have a 

material impact on the immunogenicity of MenQuadfiTM. Likewise, when MenQuadfiTM was 

given with Tdap and HPV, MenQuadfiTM did not have a material impact on the response 

following HPV vaccination at the specified seroconversion rates.

Looking at the Tdap component, seroprotection rates for diphtheria and tetanus following 

concomitant MenQuadfiTM, Tdap, and HPV vaccination were non-inferior to the seroprotection 

rates observed after Tdap and HPV without MenQuadfiTM. Non-inferiority of pertussis antibody 
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responses was considered met if the lower bound of the 95% confidence interval around the 

geometric mean concentration (GMC) ratio of Group 3 over Group 4 was greater than 0.667. 

Based on that definition, non-inferiority was met for the pertussis toxin (PT) antigen and not met 

for filamentous haemagglutinin (FHA), pertactin (PRN), and fimbriae (FIM). Lower antibody 

responses to pertussis antigens have been observed in trials in which other quadrivalent 

conjugate meningococcal vaccines have been co-administered with pertussis-containing 

vaccines. The clinical significance of any of these findings is unknown, since no antibody 

correlate of protection exists for pertussis.

Moving on to the study of MenQuadfiTM in adults 56 years of age and older, participants were 

assigned to received either MenQuadfiTM or the plain polysaccharide vaccine Menomune®. The 

mean age of the study population was just over 72 years. Solicited reactions were higher in the 

MenQuadfiTM compared to the plain polysaccharide group. There are likely two reasons for this, 

especially with regard to injection site reactions: 1) MenQuadfiTM contains tetanus toxoid as its 

protein conjugate whereas Menomune® does not have a protein conjugate; and 2) MenQuadfiTM 

is administered intramuscularly and the plain polysaccharide vaccine is administered 

subcutaneously. In terms of immunogenicity, MenQuadfiTM induced seroresponses that were 

non-inferior to those induced by the comparator vaccine. Point estimates were consistently 

higher. In this case, the 95% confidence intervals were not overlapping. A similar pattern was 

seen with seroprotection rates, with the exception of serogroup A for which the 95% confidence 

intervals did overlap. MenQuadfiTM induced GMTs that were higher than those induced by the 

comparator vaccine, especially for serogroup C.

MET56 was a study of MenQuadfiTM when used as a booster. In this trial, over 800 individuals 

15 years of age and older participated. To be eligible for participation, they had to have been 

primed with either MenACWY-D or MenACWY-CRM. They were randomly assigned to receive 

either MenQuadfiTM as a booster or MenACWY-D as a booster. The mean age was 20 years. 

Injection site and systemic reactions were similar between the two vaccine groups when they 

were used as boosters. MenACWY-TT as a booster induced a response rate that was noninferior to MenACWY-D when used as a booster. Both vaccines induced high seroprotection 

rates ranging from 99% to 100%. Both vaccines induced robust booster responses in terms of 

GMTs, but especially MenQuadfiTM and especially for serogroup C.

In MET35, MenQuadfiTM was evaluated in a trial of 1000 children 2 through 9 years of age. Half 

were randomly assigned to receive MenQuadfiTM and the other half to receive MenACWY-CRM. 

The mean age of the study population was 6 years. The frequency of solicited reactions was 

similar between the two vaccine groups, except that there was a slightly higher trend toward a 

high frequency of injection site reactions among those who received the comparator. 

MenQuadfiTM induced seroresponse rates that were non-inferior to the comparator vaccine. 

Point estimates were consistently higher for MenQuadfiTM. With the exception of serogroup A, 

the 95% confidence intervals were not overlapping. The same pattern was seen with respect to 

seroprotection rates and GMTs, with the most pronounced difference for serogroup C.

MET43 was a study of MenQuadfiTM in adolescents and adults 10 through 55 years of age. 

Over 3300 persons participated in this trial and were randomly assigned to receive either 

MenQuadfiTM from one of three vaccine lots or MenACWY-D. The mean age of the study 

population was just over 27 years. Solicited reactions occurred with similar frequency between 
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the two vaccines. MenQuadfiTM induced seroresponse rates that were non-inferior to those 

induced by the comparator vaccine. Point estimates were consistently higher with nonoverlapping confidence intervals. The same pattern was seen with respect to seroprotection 

rates and post-vaccination GMTs, with the most pronounced difference for serogroup C.

In closing, MenQuadfiTM was demonstrated to be safe and to induce a robust immune response 

against serogroups A, C, W, and Y, especially serogroup C. Immune responses were 

consistently non-inferior to standard-of-care vaccines across age groups ≥ 2 years for all 4 

vaccine serogroups. MenQuadfiTM induced booster responses among persons previously 

primed with MenACWY-D or MenACWY-CRM. Clinical trial data show that MenQuadfiTM can be 

co-administered with the routinely recommended adolescent vaccines Tdap and HPV. 

MenQuadfiTM has been licensed for use in persons 2 years of age and older. Sanofi Pasteur will 

be distributing doses of the vaccine in the US in 2021 to help support meningococcal 

vaccination efforts. Trials are ongoing to seek expansion of the age indication down to children 

6 weeks of age and to evaluate MenQuadfiTM in a number of different dosing intervals and along 

with other routinely recommended pediatric vaccines with the hope of MenQuadfiTM being 

incorporated in the different immunization schedules that exist around the world. Sanofi Pasteur 

believes that MenQuadfiTM has the potential to provide effective protection against invasive 

disease caused by serogroups A, C, W, and Y in a variety of settings.

Discussion Points

Dr. Messonnier requested that Sanofi Pasteur comment on their plans for Menactra® in terms of 

whether that vaccine will continue to be available.

Dr. Robertson indicated that the plan is to transition from Menactra® to MenQuadfiTM. Given that 

Menactra® is registered in over 70 countries, that transition will take some time and certainly will 

not occur before age indication for MenQuadfiTM is achieved down to 6 weeks of age.

Referring to slide 11, Dr. Bernstein noted that there were injection site reactions with both 

meningococcal vaccines and when MenACYW-TT was given with Tdap and HPV vaccines, but 

there appeared to be no injection site reactions at all for the group who received only Tdap and 

HPV.

Dr. Robertson clarified the study was designed to look at injection site reactions specifically 

related to the MenACWY vaccine recipient groups. Because of this, injection site reactions in 

the group who received only Tdap and HPV are not reported in the slide. This is not to say that 

this group did not have any injection site reactions.

Dr. Fryhofer (AMA) inquired as to how the tetanus toxoid component affects vaccination with 

tetanus vaccination and reactions among patients who also receive Tdap or Td.

Referring to slides 17 and 18, Dr. Robertson indicated that when MenQuadfiTM was given with 

Tdap, no impact was observed on tetanus and diphtheria responses. In terms of non-inferiority 

of pertussis antibody responses, non-inferiority was met for 1 of the 4 antigens and was 

narrowly missed for FHA and pertactin. A similar reduction in antibody response to pertussis 

antigens has been observed in other studies in which meningococcal vaccine has been given 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

17

with pertussis-containing vaccines. Sanofi Pasteur does not anticipate that this will be an issue 

clinically, given that they also assessed vaccine response with respect to these antigens and 

across the board they were high. The data presented have been published.

Following up on Dr. Fryhofer’s comment, Dr. Hunter noted that after multiple doses of tetanus 

vaccine are given, there is stronger local swelling and pain at the injection site. This can be 

significant after 5 to 7 doses. If this is done in series over time in a person’s lifetime, he 

wondered if they would have significant local reactions. Typically, this would not be dangerous 

but could be quite painful possibly in a small number of people. He asked whether that had 

occurred in any of the studies.

Dr. Robertson indicated that they do not have data in situations where Tdap or Td was given 

repeatedly for boosters along with MenQuadfiTM; however, this will certainly be monitored for in 

the future.

MenACWY-TT (MenQuadfiTM): EtR, GRADE, and WG Considerations 

Lucy McNamara, PhD, MS

National Center for Immunization & Respiratory Diseases

Centers for Disease Control and Prevention

Dr. McNamara presented a brief overview of current serogroup A, C, W, Y, or MenACWY 

vaccine recommendations and available vaccines; reviewed the policy question and the EtR 

framework for inclusion of MenACWY-TT as an option for meningococcal ACWY vaccination; 

briefly touched on all of the points in the EtR, but focused on the benefits and harms section 

including GRADE; and reviewed the considerations and conclusions of the meningococcal 

vaccines ACIP working group on this issue. The following table shows the MenACWY vaccines 

referenced during this presentation: 

The first two vaccines in the table, MenACWY-D and MenACWY-CRM, are the vaccines 

currently in use in the US. Note that while MenQuadfiTM was referred to as MenACYW-TT by 

the manufacturer, for consistency MenACWY-TT was used in this presentation. Menomune®, or 

MPSV4, is no longer available in the US. and Nimenrix®, or MCV4-TT, has never been licensed 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

18

in the US. While MenQuadfiTM and Nimenrix® are both tetanus toxoid-conjugate vaccines, they 

have different amounts of meningococcal antigens and tetanus toxoid carrier protein.

As a reminder, the current ACIP recommendations for use of MenACWY vaccine in the US are 

that 2 doses of MenACWY are recommended for adolescents at 11 through 12 and 16 years of 

age. Other individuals at increased meningococcal disease risk due either to underlying medical 

conditions or to increased exposure are also recommended to receive meningococcal vaccines, 

including boosters for those who remain at increased risk.

The policy question and PICO (population, intervention, comparison, and outcome) addressed 

in this session are shown in the following table: 

Currently, there are no data on vaccine effectiveness (VE) against serogroup A, C, W, or Y 

meningococcal disease for MenACWY-TT. The remaining four outcomes identified were 

included in the evidence profile: short-term immune response, persistence of the immune 

response induced by the vaccine, immune interference due to co-administration with other 

routine adolescent vaccines, and serious adverse events (SAEs) associated with MenACWYTT.

The first element in the EtR framework is the problem. ACIP has recognized the importance of 

meningococcal disease as a public health problem through existing vaccine recommendations. 

The WG felt that the question of whether to include MenACWY-TT as an option for 

meningococcal vaccination is of public health importance given recent licensure of this vaccine 

in the US and to support security of the vaccine supply.

For the evidence retrieval to examine benefits and harms, a systematic review was conducted 

of studies in any language from the PubMed, Medline, Embase, CINAHL, Cochrane, Scopus, 

clinicaltrials.gov, and clinicaltrialsregister.eu databases using the search string: MenACYW-TT, 

MenACYWTT, MenACYW TT, MCV4-TT, MCV4TT, MCV4 TT, MenQuadfi, and “vaccin*” and 

“(immunogenicity or efficacy or effectiveness or impact or safety or adverse event*). Efforts 

were made to obtain unpublished or other relevant data and studies were included that 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

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presented primary data on MenACWY-TT (MenQuadfiTM). The database search identified 149 

references. After screening the titles, abstracts, and articles or publicly available clinical trial 

results, 10 studies were included in the GRADE analysis. This table shows the 10 studies 

identified, all of which were Phase II or III clinical trials conducted by the manufacturer. All 10 

studies included safety data:

The first 8 studies listed had immunogenicity data, MET62 had persistence data, and MET50 

and MET57 had information on co-administration. Only MET50 included co-administration of 

routine adolescent vaccines. The data reviewed for GRADE did not include any data on 

individuals who are recommended to receive meningococcal vaccines based on underlying 

medical conditions, including persons with complement component deficiency or taking a 

complement inhibitor; persons with functional or anatomic asplenia (including sickle cell 

disease); and persons with HIV infection as these groups were excluded from the evaluated 

studies.

In terms of short-term immunogenicity assessed 30 days after vaccination with MenQuadfiTM, 

Dr. McNamara shared an example of the immunogenicity results for the MET50 study among 

individuals 10 through 17 years of age. In this study, MenACWY-TT elicited higher GMTs and a 

larger percentage of seroresponders than the comparator for all four serogroups, with the 

largest difference for serogroup C, a trend observed across all included studies. For each of the 

8 studies with data on short-term immune response, across serogroups, age groups, and 

comparator vaccines, GMTs and percentage of seroresponders were nearly always higher 

among individuals who received MenACWY-TT. All studies demonstrated non-inferiority of 

MenACWY-TT compared with the comparator vaccine.

The certainty of evidence was evaluated using GRADE. Under this approach, certainty of 

evidence is rated on a 1-4 scale with a 1 corresponding to randomized controlled trials (RCTs) 

or overwhelming evidence from observational studies; a 2 corresponding to RCTs with 

important limitations or exceptionally strong evidence from observational studies; a 3 

corresponding to observational studies or RCTs with notable limitations; and a 4 corresponding 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

20

to clinical experience and observations, observational studies with important limitations, or 

RCTs with several major limitations.

For healthy children, adolescents, and adults, the WG felt that there was no serious risk of bias, 

inconsistency, indirectness, or imprecision. The studies demonstrate that immune responses to 

MenACWY-TT are non-inferior to those induced by other licensed quadrivalent meningococcal 

vaccines with high certainty, so this criterion was rated as a 1. For groups at increased risk due 

to underlying medical conditions, indirectness was considered very serious based on the fact 

that the studies included only healthy individuals. The certainty for these groups was rated as a 

3.

The second GRADE outcome was SAEs. All 10 studies included data on SAEs. Reported rates 

of SAEs were generally low and none of the reported SAEs were determined by the researchers 

to be related to the vaccine. The highest rates of SAEs were reported in toddlers, an age group 

for which the vaccine is not currently licensed in the US. The majority of these SAEs were 

accidental injuries or infections by pathogens not included in the study vaccines. For individuals 

aged 2 years and older, including booster dose recipients, rates of SAEs were similar in the 

MenQuadfiTM and comparator groups.

For GRADE, the 9 randomized studies with safety data were included. Risk of Bias was 

considered Serious because many trials were not fully double-blinded, which could lead to bias 

in assessing SAEs. In addition, the studies did not describe how the researchers determined 

that SAEs were not vaccine-related. There were no serious concerns for inconsistency, 

indirectness, or imprecision for use of the vaccine in healthy individuals, so overall certainty was 

determined to be moderate, or 2. For people at increased meningococcal disease risk due to 

underlying medical conditions, indirectness was very serious as the studies included only 

healthy individuals, resulting in very low certainty of 4 for this group.

One study evaluated immune persistence. This study was conducted in children 4-5 years of 

age vaccinated 3 years earlier with MenACWY-TT compared with Nimenrix®, or MCV4-TT. For 

serogroups C, W, and Y, GMT ratios were greater than 1 showing higher GMTs 3 years after 

vaccination with MenACWY-TT than with the comparator. The GMT ratio for serogroup A was 

less than one. However, it is important to note that serogroup A is extremely rare in the US. This 

was a descriptive analysis so non-inferiority was not assessed. GRADing the evidence from this 

one study, the risk of bias was determined to be serious because fewer than 50% of the 

participants who received the primary vaccine dose were included in this follow-up persistence 

study. There was also serious concern for indirectness because the study was conducted in 

Finland in individuals vaccinated as toddlers, an age group for which MenACWY-TT is not 

approved in the US. Finally, there was a serious concern for imprecision because of the small 

number of participants. Overall, this brought the certainty to a very low certainty of 4 for healthy 

individuals. For the groups at increased risk due to underlying medical conditions, indirectness 

was considered very serious because the study included only healthy individuals, but overall 

certainty remains the same at 4.

In terms of the data from one study on co-administration with the routinely recommended 

adolescent vaccines HPV and Tdap, non-inferiority was demonstrated for HPV across all 4 

included HPV types when comparing co-administration of MenACWY-TT, Tdap, and HPV 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

21

vaccines to co-administration of just Tdap and HPV. MenACWY-TT responses were also noninferior when co-administered with Tdap and HPV compared to MenACWY-TT alone. For Tdap, 

non-inferiority was demonstrated for both tetanus and diphtheria antigens, and for the PT 

pertussis antigen, but not for the pertussis FHA, PRN, and FIM antigens.

Decreased immune response to the pertussis antigens included in Tdap was demonstrated in 

previous studies of co-administration of Tdap with other MenACWY vaccines1

. GMC ratios for 

pertussis antigens were similar when comparing coadministration of Tdap with MenACWY-TT or 

with currently recommended MenACWY vaccines.2 The clinical significance of these findings is 

unknown as there is no accepted correlate of protection for pertussis vaccines [1

Gasparini et al. 

(2010) “Randomized Trial on the Safety, Tolerability, and Immunogenicity of MenACWY-CRM, 

an Investigational Quadrivalent Meningococcal Glycoconjugate Vaccine, Administered 

Concomitantly With a Combined Tetanus, Reduced Diphtheria, and Acellular Pertussis Vaccine 

in Adolescents and Young Adults”; 2

Weston et al. (2011) “Immunogenicity and Reactogenicity of 

Co-Administered Tetanus-Diphtheria-Acellular Pertussis (Tdap) and Tetravalent Meningococcal 

Conjugate (MCV4) Vaccines Compared to Their Separate Administration].

For GRADE, risk of bias in this one available study was classified as serious due to the reduced 

number of participants evaluated for HPV immunogenicity, for which no explanation could be 

identified from the published article. There were no serious concerns about indirectness or 

imprecision for healthy individuals, so overall certainty was a 2. For the groups at increased risk 

due to underlying medical conditions, indirectness was considered very serious based on the 

fact that studies included only healthy individuals, bringing the overall certainty to a 4.

While PCV13 is not a routine adolescent vaccine and therefore co-administration issues with 

this vaccine were not included as an outcome for GRADE, PCV13 is also recommended for 

individuals who are recommended to receive MenACWY because they have medical conditions 

that increase risk of meningococcal disease. One study assessed co-administration of 

MenACWY-TT and PCV13 in toddlers and no evidence was found of immune interference 

between these vaccines.

To summarize the GRADE assessment, for healthy individuals the WG rated the certainty of 

evidence as 1 for short-term immunogenicity, 4 for persistence, and 2 for co-administration of 

routine adolescent vaccines and SAEs. However, for people with medical conditions increasing 

their risk of meningococcal disease, the quality of evidence was rated as a 3 for short-term 

immunogenicity and 4 for the other outcomes.

Overall, the WG felt that the desirable effects outweigh the undesirable effects, favoring 

inclusion of MenACWY-TT as an option for MenACWY vaccination. For the values, 

acceptability, and feasibility sections of the EtR framework, the WG felt that the 86.6% 

vaccination coverage in 2018 for at least one dose of MenACWY vaccine1 among adolescents 

demonstrates that the target population values and accepts this intervention and that it is 

feasible with current vaccination platforms. However, there are limited data on uptake among 

other individuals recommended to receive MenACWY vaccine such as microbiologists or 

individuals with medical conditions that increase meningococcal disease risk. It is not expected 

that values, acceptability, or feasibility would differ for MenACWY-TT compared with currently 

available meningococcal conjugate vaccines [1

Walker TY, Elam-Evans LD, Yankey D, et al. 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

22

National, Regional, State, and Selected Local Area Vaccination Coverage Among Adolescents 

Aged 13–17 Years — United States, 2018. MMWR Morb Mortal Wkly Rep 2019;68:718–723. 

DOI: http://dx.doi.org/10.15585/mmwr.mm6833a2]. 

For resource use, the manufacturer has indicated that the projected cost of MenACWY-TT will 

be within 5% of the cost of currently licensed and available MenACWY vaccines, so resource 

allocation will not be substantively affected by inclusion of MenACWY-TT as an option for 

MenACWY vaccination.

To summarize the EtR assessment, the WG felt that for the question of whether to include 

MenACWY-TT as an option for meningococcal ACWY vaccination, the problem was of public 

health importance. While the desirable anticipated effects are small, the undesirable ones are 

minimal therefore favoring intervention with a certainty of evidence that varies from high to very 

low across critical outcomes and populations recommended for vaccination. The WG believes 

that the target population does feel that the desirable effects outweigh undesirable effects with 

probably no important uncertainty or variability in how much people value the main outcomes, 

that the intervention is acceptable to key stakeholders, that it is a reasonable allocation of 

resources, and that it is feasible to implement.

Overall, it was felt that the desirable consequences probably outweigh undesirable 

consequences in most settings. The WG’s interpretation was that there was sufficient 

information to include MenACWY-TT as an option for meningococcal ACWY vaccination 

according to currently recommended dosing and schedules. This would apply only for 

individuals aged 2 years and up, the ages for which the vaccine is licensed in the US. The WG 

was in agreement on this.

Of note, several of the current recommendations for use of MenACWY are off-label for all 

currently licensed MenACWY vaccines, including the 2-dose primary series for groups with 

specified underlying medical conditions; all booster doses among persons aged <15 years; and 

boosters beyond the first for individuals who are recommended to receive boosters every 3 to 5 

years. For MenACWY-D and MenACWY-CRM, but not for MenACWY-TT, use in persons aged 

greater than 55 years is also off-label.

Implementation of MenACWY-TT as an option for MenACWY vaccination does not represent a 

change in policy or ACIP recommendations and therefore, no ACIP vote is required. However, a 

VFC vote and updated VFC resolution are required to include MenACWY-TT as an option in the 

VFC program.

Discussion Points

Because MenACWY-TT is not approved for people less than 2 years of age who are at high 

risk, it will be very important moving forward to ensure that there continues to be a vaccine for 

children 2 months to 2 years of age.

Dr. Lee recognized and appreciated that the trials incorporated racial and ethnic diversity that 

was representative of the population. She expressed her hope that this would become the norm, 

but emphasized the importance of this in current and future conversations.
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

23

Dr. Sanchez expressed concern about the lower pertussis antibody titers for certain antigens as 

more pertussis disease and outbreaks are seen in the US. While there are no defined protective 

levels, he stressed the importance of studying this in the future.

Dr. Barnett (ISTM) pointed out that while serogroup A disease may be rare in the US, it is one of 

the most common for travelers. She wondered whether the WG expressed any concern about 

the lower GMT response for serogroup A.

Dr. McNamara clarified that the lower GMT response for serogroup A that she mentioned was 

specifically for the persistence study in which MenQuadfiTM was being compared with 

Nimenrix®, which is a vaccine that is not currently licensed in the US. In all of the studies 

assessing short-term immunogenicity, non-inferiority was demonstrated for immune response 

for MenQuadfiTM compared to the vaccines currently available in the US. 

Given that MenQuadfiTM is conjugated to tetanus toxoid, Dr. Fryhofer (AMA) requested 

clarification as to whether this would affect receiving tetanus boosters and would provide any 

protection against tetanus.

Dr. McNamara clarified that the vaccine is licensed for protection against meningococcal 

disease, but she did not believe the ability of the vaccine to protect against tetanus has been 

assessed.

Dr. Robertson added that Sanofi Pasteur has taken the opportunity to assess anti-tetanus 

responses, which are on par with levels that would be considered seroprotective. However, the 

vaccine is not indicated for use in prevention of tetanus.

VFC Resolution Update: Meningococcal Vaccines

Frank Whitlatch

Immunization Services Division

National Center for Immunization and Respiratory Diseases

Centers for Disease Control and Prevention

Mr. Whitlatch indicated that the purpose of this presentation was to update the resolution to 

reflect currently available meningococcal conjugate vaccines that can be used to prevent 

meningococcal disease attributable to serogroups A, C, W, and Y. He pointed out that yellow 

font/highlight in the presentation was used to indicate changes to the resolution in comparison 

to the prior approved version.

No changes were made to the eligible groups for MenACWY:

Eligible Groups 

• Children aged 2 months through 10 years who are at increased risk for meningococcal 

disease attributable to serogroups A, C, W, and Y, including:

– Children who have persistent complement component deficiencies (including inherited 

or chronic deficiencies in C3, C5-C9, properdin, factor H, or factor D)
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

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– 

–

– 

– 

– 

Children taking a complement inhibitor (e.g., eculizumab [Soliris], ravulizumab 

[Ultomiris])

Children who have anatomic or functional asplenia, including sickle cell disease

Children infected with Human Immunodeficiency Virus (HIV)

Children traveling to or residing in countries in which meningococcal disease is 

hyperendemic or epidemic, particularly if contact with local population will be 

prolonged

Children identified to be at increased risk because of a meningococcal disease 

outbreak attributable to serogroups A, C, W, or Y

• All children aged 11 through 18 years

A new table was added to cover all vaccine types covered by this section of the resolution, 

which the previous resolution did not include:

The Menactra® and Menveo® information reflects previously published ACIP recommendations, 

while the MenQuadfiTM information is new.

The recommended schedules and intervals for meningococcal conjugate vaccines have not 

changed and can be found at the following links:

• http://www.cdc.gov/mmwr/pdf/rr/rr6202.pdf

• http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6324a2.htm

• https://www.cdc.gov/mmwr/volumes/65/wr/mm6543a3.htm

The recommended dosage and contraindications and precautions also have not changed:

Recommended dosage 

Refer to product package inserts. 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

25

Contraindications and Precautions

Contraindications and Precautions can be found in the package inserts available at 

https://www.fda.g

For serogroup B, the eligible groups have not changed: 

Eligible Groups 

• Children aged 10 through 18 years at increased risk for serogroup B meningococcal 

disease, including:

– 

– 

– 

– 

Children who have persistent complement component deficiencies (including 

inherited or chronic deficiencies in C3, C5-C9, properdin, factor H, or factor D.

Children taking a complement inhibitor (e.g., eculizumab [Soliris], ravulizumab 

[Ultomiris]) 

Children who have anatomic or functional asplenia, including sickle cell disease

Children identified to be at increased risk because of a meningococcal disease 

outbreak attributable to serogroup B

• Children aged 16 through18 years who are not at increased risk for serogroup B 

meningococcal disease may also be vaccinated

The recommended vaccination schedule and intervals have not changed:
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

26

The recommended dosage and contraindications and precautions have not changed:

Recommended dosage 

Refer to product package inserts. 

Contraindications and Precautions

Contraindications and Precautions can be found in the package inserts available at 

https://www.fda.gov/vaccines-blood-biologics/vaccines/vaccines-licensed-use-united-states 

The statement regarding updates based on published documents has not changed:

[If an ACIP recommendation regarding meningococcal vaccination is published within 6 months 

following this resolution, the relevant language above (except in the eligible groups sections) will 

be replaced with the language in the recommendation and incorporated by reference to the 

publication URL.]

Motion/Vote: VFC Resolution for Meningococcal Vaccines

Dr. Szilagyi made a motion to approve the VFC Resolution as presented. Dr. Poehling 

seconded the motion. No COIs were declared. The motion carried with 14 affirmative votes, 0 

negative votes, and 0 abstentions. The disposition of the vote was as follows:

14 Favored: Atmar, Ault, Bahta, Bell, Bernstein, Frey, Hunter, Lee, McNally, Poehling,

Romero, Sanchez, Szilagyi, Talbot

 0 Opposed: N/A

 0 Abstained: N/A

Introduction

Robert L. Atmar, MD

Chair, Influenza Work Group

Baylor College of Medicine

Dr. Atmar reminded everyone that during the February 2020 ACIP meeting there was an 

overview of early 2019-2020 season influenza activity; a presentation of early season 2019-

2020 influenza vaccine effectiveness (VE) estimates; a presentation from SeqirusTM on FLUAD®

Quadrivalent that was licensed by the Food and Drug Administration (FDA) on February 21, 

2020; and a presentation of safety data from a comparative randomized controlled trial (RCT) of 

high-dose and adjuvanted inactivated influenza vaccines among older adults. 

Influenza
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

27

Since that meeting, the WG has been discussing development of the proposed 2020-2021 ACIP 

influenza statement. The agenda for this session included presentations on 2019-2020 influenza 

activity, VE, and safety updates; and WG considerations and proposed 2020-2021 

recommendations. 

WG Considerations and Proposed Recommendations

Lisa Grohskopf, MD, MPH

Influenza Division, CDC

National Center for Immunization and Respiratory Diseases

Centers for Disease Control and Prevention

Dr. Grohskopf began with an update of 2019-2020 influenza activity. Starting with virologic 

surveillance, she reviewed the results of influenza positive tests reported to CDC weekly from 

US clinical and public health laboratories. Based on the clinical laboratories, influenza B viruses 

predominated early in the season, but with time, there was an increasing presence of influenza 

A viruses, such that by the season taken as a whole, identified specimens were roughly divided 

between influenza A and B viruses. There is more information with the public health 

laboratories, since they generally provide subtype and lineage. Overall, the predominant virus 

groups were H1N1pdm09 and B/Victoria. An additional point for the clinical laboratories, the 

percent of specimens that were positive was decreasing steeply from about week 8 through 12 

or 14 of 2020. 

Surveillance data for influenza-like illness (ILI) come from ILINet, a network of providers who 

report weekly the percent of outpatient visits that were for ILI. For the most recent season, 

2019-2020, there was relatively high ILI activity from late December through February, with two

separate peaks. Then there was a third peak. Because this is ILI, which uses a symptom- or 

syndromic-based definition rather than laboratory confirmation of influenza, other pathogens 

besides influenza could be involved. By the time of the third peak, it is known from other 

surveillance indicators that influenza was still circulating, but activity had already begun to fall 

pretty dramatically. It also is known that severe acute respiratory syndrome coronavirus 2 

(SARS-CoV-2) activity was increasing at that time and so it was assumed that the third peak 

was due in a large part to coronavirus disease 2019 (COVID-19) rather than influenza. 

In terms of influenza-associated hospitalizations based on data from FluSurv-net for cumulative 

hospitalization rates per 100,000 for laboratory-confirmed influenza, between October 1, 2019 

and April 30, 2020, the cumulative hospitalization rate was approximately 69 per 100,000 

population. This is considerably less than the pretty severe 2017-2018 season but was higher 

than recent non-pandemic seasons. 

Mortality data from the National Center for Health Statistics (NCHS) come from death certificate 

diagnoses and are reported as the percent of deaths due to pneumonia- and influenza-coded 

diagnoses. These are diagnostic code data, not laboratory confirmed influenza. For the earlier 

part of the season, values were relatively low, but then there was a large peak in pneumonia 

and influenza deaths in the latter part of the season. This is thought to be largely due to COVID19.
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

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In terms of pediatric mortality associated with laboratory confirmed influenza, which has been 

reportable since 2004, there were 185 pediatric deaths reported to CDC for the 2019-2020 

season as of the most recent reporting week. This is unfortunately fairly close to the 188 

reported for 2017-2018. Among these deaths, 71 were associated with influenza A viruses and 

114 were associated with influenza B viruses. In general, for the past number of seasons with 

these data, among those children who are eligible for vaccination and for whom vaccination 

information is available, the majority were not vaccinated. Generally, around 20% were 

vaccinated. Thus far with the available data for 2019-2020, it appears that approximately 20% 

were vaccinated.

For the past several seasons, CDC has published estimates of influenza burden in the US. The 

preliminary estimates cover the period between October 1, 2019 and April 4, 2020. The 

estimates are that there were between 39 million and 56 million influenza illnesses, between 18 

million and 26 million influenza-associated medical visits, between 410,000 and 740,000

influenza-related hospitalizations, and between 24,000 and 62,000 influenza-related deaths.

The next estimates come from the US Flu VE Network. As a reminder, the US Flu VE Network 

is a network of 5 healthcare organizations for which the locations and Principal Investigators are 

as follows:

 Baylor Scott and White Health: Manju Gaglani

 Kaiser Permanente Washington: Mike Jackson & Lisa Jackson

 Marshfield Clinic Research Institute: Ed Belongia & Huong McLean

 University of Michigan: Arnold Monto & Emily Martin

 University of Pittsburgh: Rick Zimmerman & Tricia Nowalk

At these sites, the network enrolls outpatients ≥6 months of age with acute respiratory illness 

with cough of ≤7 days duration. Dates of enrollment are between October 29, 2019 through 

March 26, 2020. The network uses a test-negative design, which involves comparing 

vaccination odds among influenza reverse transcriptase polymerase chain reaction (RT-PCR) 

positive cases and RT-PCR negative controls. Vaccination status is defined as receipt of at 

least one dose of any 2019-2020 seasonal influenza vaccine according to medical records, 

immunization registries, and/or self-report. VE is calculated as (1 – adjusted OR) x 100%. 

Adjustments are made for study site, age, sex, self-rated general health status, race/Hispanic 

ethnicity, interval from onset to enrollment, and calendar time. 

Regarding preliminary end-of-season 2019-2020 influenza VE from the US Flu VE Network as 

of June 9, a total of 8844 patients were enrolled. Of these, 2743 (31%) were RT-PCR positive

and 6121 (69%) were RT-PCR negative. Among those who were PCR positive, the breakdown 

by influenza virus type, subtype, and lineage was that about half (51%) were influenza 

A(H1N1)pdm09; 44% were B Victoria; and relatively little were H3N2 and B/Yamagata viruses.

In terms of the preliminary VE estimates, estimated VE was 39% for any influenza, 31% for 

influenza A(H1N1)pdm09, and 44% for influenza B/Victoria overall across age groups. All of 

these estimates are statistically significant. Looking at VE against H1N1pdm09 viruses by age 

group, there was statistically significant VE of 45% among adults 50-64 years of age. The VE 

point estimate was a little lower at 38% for those aged 65 and older, with the lower limit of the 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

29

confidence interval here being 0. Estimated VE was lower in the 22% to 29% range for younger 

adults and for children was not statistically significant for either of the pediatric age groups. For 

influenza B/Victoria viruses, VE point estimates were similar across age groups in the 38% to 

44% percent range and were statistically significant among children and young adults. They 

were not statistically significant for those 50 years of age and older.

In summary for this section, preliminary results for the 2019-2020 season indicate 39% (95%CI: 

32, 45) VE against medically attended influenza. Vaccine provided important protection against 

influenza B viruses, given the severity of 2019-2020 season for children. Protection against 

A/H1N1pmd09 viruses was lower than previous seasons. Investigation of contributing factors for 

these results is ongoing. Finally, note that preliminary end-of-season estimates use best 

available information on vaccination status of the participants at the time presented. These 

estimates will be revised as data are finalized. 

An end-of-season safety update is normally presented during June ACIP meetings, so Dr. 

Grohskopf presented data on the 2019-2020 season influenza vaccine safety. First, two 

disclaimers: 1) The findings and conclusions in this presentation are those of the authors and do 

not necessarily represent the official position of CDC and FDA; and 2) The use of product trade 

names is for identification purposes only. 

Beginning with a brief summary of 2019-2020 influenza vaccine safety surveillance, 

approximately 174.5 million doses of influenza vaccine were distributed in the US through 

February 28, 20201

. CDC and FDA analyzed spontaneous reports to the Vaccine Adverse Event 

Reporting System (VAERS). No new safety concerns were identified for any influenza vaccine 

types. In addition, CDC conducted near real-time sequential monitoring through Rapid Cycle 

Analysis (RCA) in the Vaccine Safety Datalink (VSD). Approximately 5.8 million doses of 

influenza vaccine were administered at VSD sites through March 7, 2020. No new safety 

concerns were identified for any influenza vaccine types in this analysis [1

CDC Seasonal 

Influenza Vaccine Supply & Distribution: https://www.cdc.gov/flu/prevent/vaccine-supplydistribution.htm].

Dr. Grohskopf also presented information about a study in progress, the Clinical Immunization 

Safety Assessment (CISA) Project study of the safety of quadrivalent recombinant influenza 

vaccine (RIV4) versus quadrivalent inactivated influenza vaccine (IIV4) among pregnant 

women. This is a randomized observer- and participant-blinded clinical trial. The study 

population consists of pregnant women aged ≥18 years who are at gestational age ≤34 weeks 

at the time of vaccination. Participants are randomized 1:1 to receive RIV4 (Flublok®

Quadrivalent) or IIV4 (Flulaval® Quadrivalent). Maternal and infant safety outcomes are 

collected from enrollment through 90 days postpartum and local and systemic reaction data are 

collected from vaccination day through Day 8 after vaccination. Blood is collected at baseline 

and 28 days after vaccination for immunogenicity assessment. Participants are being enrolled 

from 3 sites during the 2019-2020 and 2020-2021 influenza seasons, with a total goal of 430 

participants. To date, this study has enrolled and randomized 233 participants during the 2019-

2020 season. A safety review was held in which a panel of three medical experts who are not 

study investigators reviewed the interim safety data for serious adverse events (SAEs). Each 

panel member concluded there were no substantial safety concerns observed. The current plan 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

30

is to continue enrollment in 2020-2021 influenza season. More information will be presented on 

this study at a later meeting.

Turning to WG considerations and the proposed 2020-2021 recommendations, Dr. Grohskopf

outlined the proposed changes to the influenza statement for the 2020-2021 season. The core 

recommendation is unchanged. Annual influenza vaccination is recommended for all persons 6 

months of age and older who do not have contraindications. There are two primary updates to 

the recommendations: 1) the US influenza vaccine viral composition, which has been updated 

for 2020-2021; and 2) inclusion of two recently licensed vaccines, Fluzone® High-Dose 

Quadrivalent and Fluad® Quadrivalent.

With regard to vaccine composition for 2020-2021, there have been updates to the influenza 

A(H1N1)pdm09, influenza A(H3N2), and influenza B/Victoria components. The B/Yamagata 

component is the same as last season. Note that for this season, a different composition is 

specified for egg-based versus non-egg-based vaccines, at least for influenza A viruses. These 

are not actually distinctly different vaccine compositions. For several years, FDA has specified 

different reference strains for egg- versus cell-based vaccines. It is just being explicitly stated 

now. Generally, the viruses are referred to as pdm09-like viruses and H3N2-like viruses. For 

any particular target virus that is desired to target for the coming seasons, there are several 

possibilities for suitable viruses. That is reflected here:

Egg-based influenza vaccines will contain hemagglutinin derived from:

 an A/Guangdong-Maonan/SWL1536/2019 (H1N1)pdm09-like virus;

 an A/Hong Kong/2671/2019 (H3N2)-like virus;

 a B/Washington/02/2019 (Victoria lineage)-like virus; and

 (for quadrivalent vaccines) a B/Phuket/3073/2013 (Yamagata lineage)-like virus.

Non-egg-based influenza vaccines will contain hemagglutinin derived from:

 an A/Hawaii/70/2019 (H1N1)pdm09-like virus;

 an A/Hong Kong/45/2019 (H3N2)-like virus;

 a B/Washington/02/2019 (Victoria lineage)-like virus; and

 a B/Phuket/3073/2013 (Yamagata lineage)-like virus.

 

The second primary update is that there are two new influenza vaccines that were licensed after 

the publication of the 2019-2020 statement, which are expected to be available for the first time 

during 2020-2021. First, in November 2019, the FDA licensed Fluzone® High-Dose Quadrivalent 

from Sanofi Pasteur for ages 65 years and older. Like the previous trivalent high-dose vaccine, 

this vaccine contains 60 micrograms of hemagglutinin per vaccine virus for a total of 240 

micrograms in a 0.7 milliliter dose. The 0.7 milliliter dose volume is slightly higher than that for 

all other injectable vaccines, including the previous trivalent version of Fluzone® High-Dose, 

which is 0.5 milliliters. This vaccine will replace the previous trivalent Fluzone® High-Dose for 

2020-2021. Pre-licensure data were presented to the ACIP in October 2019. In February 2020, 

the FDA licensed Fluad® Quadrivalent from SeqirusTM for persons ages 65 years and older. This 

vaccine contains MF59 adjuvant similarly to the previously licensed trivalent formulation of 

Fluad®. Pre-licensure data were presented to the ACIP in February 2020. 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

31

There are several other notable changes and clarifications. First, in the Contraindications and 

Precautions table (Table 2), the text of the header which previously read “Contraindications and 

conditions for which use is not recommended” has been changed to “Contraindications.” The 

original header reflected the fact that for one of the vaccines, live attenuated influenza vaccine 4

(LAIV4), there are some labeled contraindications that are listed in the package insert, and 

others which are not labeled contraindications but instead are situations in which ACIP 

recommends that LAIV4 not be used. However, following discussion of this issue in the context 

of the adult and pediatric schedules at the October 2019 ACIP meeting and ensuing WG 

discussions, the WG consensus was that it was clearer to simply to call these 

“Contraindications” in the table. The text of the document provides more detail concerning which 

contraindications are labeled contraindications in the package insert, and which are ACIP 

recommended contraindications.

There is another change to the contraindications and precautions table, which involves use of 

LAIV4 in specific populations: those with cochlear implants, active cerebrospinal fluid (CSF) 

leaks, and anatomic or functional asplenia. The text previously indicated in the section on 

vaccination of immunocompromised persons that vaccines other than LAIV4 should be used in 

these populations. The basis for this was the fact that LAIV4 is a live vaccine, the lack of data 

on use of LAIV4 in these groups, and the availability of alternative vaccines. These conditions 

were not explicitly listed separately in the contraindications table, however. The WG recently 

revisited this issue. To help inform this WG discussion, the Immunization Safety Office (ISO)

conducted a targeted review in VAERS for LAIV-related reports in populations with asplenia or 

sickle cell disease and those with CSF leak or cochlear implant. As a reminder, VAERS is the 

US spontaneous reporting surveillance system which has been operating since 1990 and is

co-managed by CDC and FDA. VAERS receives AE reports from manufacturers, medical 

providers, vaccine recipients, and the general public. 

In a review of primary US reports between July 1990 and March 16, 2020, the vaccines included 

were LAIV (whether monovalent, trivalent or quadrivalent) with or without other vaccines. There 

were no age restrictions. Search methods used included Medical Dictionary for Regulatory 

Activities (MedDRA) preferred terms and text string search. This search yielded two reports 

related to asplenia or sickle cell disease. For sickle cell disease, there was 1 non-serious report 

in a child. For asplenia/splenectomy, there was 1 death report in an adult. There were 3 reports 

related to cochlear implant, all non-serious reports in children. There were no reports for CSF 

leaks. In addition, a literature search developed with a librarian using terms based on “influenza 

vaccine” and “Cochlear implant,” “cerebrospinal fluid leak,” “CSF leak,” “anatomic asplenia,” 

“functional asplenia,” or “sickle-cell anemia” was performed. This yielded 141 citations, but no 

data related to use of LAIV in these populations. In WG discussions, in was noted that there are 

insufficient data reflecting use of LAIV4 in these populations. There are also alternative 

influenza vaccines available. In the proposed document, these conditions have been added to 

the list of contraindications for LAIV4 specifically in the table. 

The last update concerns use of influenza antivirals and LAIV4. The statement has for several 

years previously indicated that use of influenza antivirals from 48 hours before to 2 weeks after 

administration of LAIV4 may interfere with the effectiveness of vaccine, since LAIV4 contains 

live virus that must replicate in the nasopharynx. This time interval is noted in the package insert 

for LAIV4. However, the newer antivirals peramivir and baloxavir have longer half-lives than 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

32

oseltamivir and zanamivir. Unfortunately, insufficient data are available concerning use of LAIV 

in the setting of influenza antiviral use. It is unknown whether and to what extent interference 

with the vaccine might occur. However, it seems biologically plausible that interference could 

occur. In discussion of these issues within the WG, the following was proposed. Based on the 

half-lives of the antivirals, and assuming a minimum of 5 half-lives after the last dose being 

needed for adequate washout of antiviral, language has been added indicating that it is prudent 

to assume interference might be possible if antivirals are administered within these intervals:

Antiviral Interval

Oseltamivir and Zanamivir 48 hours before to 2 weeks after LAIV4

Peramivir 5 days before to 2 weeks after LAIV4

Baloxavir 17 days before to 2 weeks after LAIV4

Language concerning persons with a history of severe allergic reaction to egg (e.g., having had 

any symptom other than hives after egg ingestion) has been updated to reflect availability of two 

egg-free vaccines, the cell-culture based inactivated vaccine (ccIIV4) and the recombinant 

influenza vaccine (RIV4). For the last several seasons for individuals with a history of severe 

reaction to egg, the language has specified that those individuals should be vaccinated in a 

medical setting under the supervision of a health care provider who is able to recognize and 

manage severe allergic reactions. However, this season that language has been updated to 

indicate that for these individuals, these conditions hold if a vaccine other than ccIIV4 or RIV4 is 

used.

To summarize the proposed changes, principal changes include the 2020-2021 US influenza 

vaccine composition and inclusion of Fluzone® High-Dose quadrivalent and Fluad® Quadrivalent 

for adults aged 65 years and older. Other changes include that Table 2 now says

“Contraindications” rather than “Contraindications and conditions for which use is not 

recommended.” Asplenia, cochlear implant, and active CSF leak are included as 

contraindications in Table 2. There is updated guidance concerning LAIV4 and influenza 

antivirals based on half-lives of the various agents. Updated language is included concerning 

vaccination of persons with egg allergy to reflect availability of egg-free vaccines. 

Discussion Points

Referring to Slide 16, Dr. Lee observed that there were higher estimates noted against 

H1N1pdm09 in adults 50 years of age and older. Given the age differences noted, she 

wondered whether prior receipt of influenza vaccine was assessed as a potential reason for 

those differences.

Dr. Grohskopf indicated that she did not have that information at this time. In a number of 

previous seasons, the Flu VE Network has managed to perform analysis assessing various 

seasons of prior vaccination history. She anticipated that they might do the same in the future 

and recognized this as an important question.

Dr. Szilagyi asked whether there is any updated information on LAIV use in the Flu VE Network 

data. He also noted that there was a difference in VE for influenza A versus B among children 

for both age groups with confidence intervals just barely crossing 0. He suggested that it may be 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

33

helpful in future presentations to show the VE for the combination for all influenza. Looking at 

the point estimates and confidence intervals, he felt sure there would be significant VE for 

children for both age groups if combined. Related to that overall VE, he thought it was always 

worth emphasizing that a VE of almost 40% means a reduction of 40% of outpatient influenza 

patient medically attended visits. Although lower than hoped, it is a significant reduction in 

morbidity due to influenza vaccine. 

Dr. Grohskopf indicated that there has not been a lot of use of LAIV within the Flu VE Network 

facilities within the last couple of seasons. She did not think that had changed for this season, 

but perhaps they will know more when those data and previous receipt history are finalized. She 

will take the comment regarding the depiction of the VE data back to the VE group.

Dr. Bernstein asked what plans might be in place for assessing influenza and SARS-CoV2 in 

the Southern Hemisphere and how that might help the Northern Hemisphere.

Dr. Grohskopf recognized this as an excellent question but was not aware of any specific plans 

at this point. She indicated that she would seek more information about that to provide later.

Dr. Bahta expressed an interest in some of the patterns in the Spring as H1N1pdm09 was rising 

followed by such a precipitous fall, and wondered whether that was a decrease that was related 

to people ceasing testing because they were testing for COVID-19 instead or if it was a true 

rapid decline.

Dr. Grohskopf said it was difficult to discern. It could be a combination of variables. By the time 

influenza activity began to decrease, that would not have been an atypical period of time 

necessarily for influenza activity to fall. The peak did seem to be running from about late 

December into February. It would not be uncommon to see that kind of a drop, although the 

point is well taken that it looks somewhat precipitous. It is difficult to say what the testing 

patterns were during that period of time.

Dr. Sanchez suggested that comments be added at least with regard to CSF leak and Cochlear 

implants that data are insufficient. When providers see the contraindication, there will be 

heightened concern if given inadvertently. Perhaps this could be reflected in a footnote.

Dr. Kimberlin (AAP) agreed with Dr. Sanchez, emphasizing that 2 reports of asplenia or sickle 

cell disease and 3 reports of CSF leak and Cochlear implants in VAER hardly seemed sufficient 

to warrant a contraindication. At the very least, mention should be made of the weakness or the 

lack of data would be warranted and that this recommendation is being made out of an 

abundance of caution or something to that effect.

Dr. Grohskopf pointed out that it is not directly noted in the table. It is noted in the text, but 

perhaps consideration could be given to adding a footnote to the table. That is more or less the 

tenor of the recommendation. There is not much in VAERS and the recommendation is largely 

based on the fact that there are alternative vaccines and some biologically plausible issues to 

be concerned about. The other issue that has to be considered is the Table of Contraindications 

should be as simple, direct, and easy to interpret as possible in that table which is a point that 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

34

was raised during the October 2019 meeting. This was the best compromise the WG could 

come up with.

Regarding the sudden decline in influenza, Dr. Hunter wondered at the end of the season 

whether that was coincident with the implementation of social distancing as COVID-19 was

getting started. It would be nice to know whether approaching seasonal influenza with targeted 

physical distancing for a limited amount of time every season might be considered for inclusion 

in influenza recommendations in the future.

Dr. Grohskopf said that could be plausible. The data in that network are national and things 

were different in various parts of the country with regard to the activity.

Dr. Atmar noted that the slide showing the decline also had a line showing the percent positive, 

which decreased precipitously at the same time the number of isolates decreased. He thought it 

was real. Anecdotally, one of his colleagues in Houston who does a lot of viral diagnostics and 

surveillance noted a precipitous change in the identification of all respiratory viruses as physical 

distancing was rolled out in their community. This probably was not unique to influenza and at 

least in the Houston area may have been associated with the social distancing measures 

instituted to try to limit the spread of COVID-19.

Given the next wave of COVID-19 anticipated in the Fall, Dr. Quach (NACI) wondered whether 

the ACIP Influenza WG was anticipating any changes in the vaccination administration program.

Dr. Cohn indicated that there would be an update later in the day on the influenza program 

implementation plans for the Fall during the COVID session.

Dr. O’Leary (PIDS) inquired as to why they continued to use the language “egg allergy” when 

there is accumulating evidence that shows individuals who are severely allergic to eggs are not 

at higher risk of anaphylaxis than the general population. He sees that as a barrier to influenza 

vaccination if primary care practitioners feel like they cannot administer the vaccine in their 

office and have to send those children to an allergist. The language is essentially identical to the 

language in the General Recommendations on immunization. All immunizing providers are 

supposed to be able to handle anaphylactic reactions. Calling out non-egg cell-based vaccines 

is creating an exception for those vaccines where there are no exceptions for any other 

vaccines to his knowledge. 

Dr. Grohskopf responded that this is a topic that has been discussed for the past several years. 

There are existing and increasing data indicating that severe allergic reactions are unlikely. 

However, the current incarnation of the language before this recent change arose out of an 

abundance of caution, and some concern during an ACIP meeting where that language was 

developed and refined, that there may settings as increasingly more people are getting 

vaccinated outside of their medical home, where it is possible that adequate equipment and/or 

personnel might not be available. The WG’s thinking is more or less that it is already reasonably 

permissive as far as location of where to vaccinate. With regard to having exceptionalism for 

ccIIV and RIV4, it seemed to make sense at this point that that should be noted since those 

vaccines are egg-free. The WG will continue to revisit this with the reviews at some point in the 

near future. They also continue to follow this in VAERS. They began looking at this for the 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

35

annual safety update in VAERS since the initial season after the recommendations changed to 

be more permissive. There have been some isolated incidences of people with a history of egg 

allergy who have had reactions. It is important to note that ccIIV and RIV4 are not going to be 

for everybody. Egg allergy tends to be more of an issue in the pediatric population. RIV4 is 

licensed for persons 18 years of age and older and ccIIV is for persons 4 years of age and up.

Dr. Fryhofer (AMA) said that speaking as a general interest in practice who sees patients, she 

greatly appreciates ACIP being very cautious in its recommendations, especially this year. With 

COVID-19 and trying to get patients immunized, influenza vaccines are likely to be given 

perhaps in some non-traditional locations. She appreciates erring on the side of caution to make 

influenza vaccination clinics as safe as possible. She thought the proposed wording would be 

helpful for clinicians and would keep everyone safe.

Dr. Bernstein asked whether Sanofi would make clear that the multi-dose vial should be used 

only for 10 doses of 0.25 ml and not more since the pre-filled 0.25 ml product will not be 

available this coming influenza season.

Dr. Rizzo (Sanofi Pasteur) indicated that he would follow up and report back later in the day.

Reflecting on what Drs. Sanchez and Kimberlin said about the wording, Dr. Lee thought it would 

be helpful to clarify how ACIP is defining “contraindication” specifically because if no other 

vaccines were available, the benefits might outweigh the risks of vaccination with LAIV for those 

who are asplenic or may have CSF leaks since there are no additional data to suggest harm. 

Another way to think about it is as a precaution, which is not their typical language for a 

preferential recommendation. That would reflect the consensus of the group without confusing 

people about the intent of the recommendation.

Motion/Vote: Changes to the ACIP Statement for Influenza Vaccines

Dr. Bell motioned to accept the changes recommended to the ACIP Statement for the 2020-

2021 influenza season. Dr. Atmar seconded the motion. No COIs were declared. The motion 

carried with 14 affirmative votes, 0 negative votes, and 0 abstentions. The disposition of the 

vote was as follows:

14 Favored: Atmar, Ault, Bahta, Bell, Bernstein, Frey, Hunter, Lee, McNally, Poehling,

Romero, Sanchez, Szilagyi, Talbot

 0 Opposed: N/A

 0 Abstained: N/A
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

36

Overview of COVID-19 Disease

John T. Brooks, MD

Chief Medical Officer, Division of HIV/AIDS Prevention

Acting Chief Medical Officer, COVID-19 Response

National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention

Centers for Disease Control and Prevention

Dr. Brooks noted that while he would not go over all of the slides during this presentation, they 

were provided in the materials and that ACIP members could reach out later with any questions 

they may have about those.

In terms of the basic structure, Coronavirinae is a single-stranded ribonucleic acid (RNA) virus 

with a genome of about 25 to 32 kilobases, which is relatively large among these types of 

viruses. Key about the structure is that it is composed of four principal proteins that all are 

required to produce a structurally complete viral particle. The most important of these is the 

spike protein that is on the outside of the virus. Inside the virus is the RNA genome surrounded 

by a nucleocapsid, the membrane protein, and the envelope protein.

Coronaviridae/-virinae belong to the order Nidovirales. Nido comes from the Latin word for nest 

and refers to a hallmark of Nidovirus transcription, also seen in all coronaviruses with the 

synthesis of the three prime co-terminals in a nested set of messenger RNA (mRNA). It is 

important to emphasize that coronaviruses comprise a very large family of viruses that infect a 

wide variety of mammals and birds. They are divided into 4 genera: Alpha-CoV, Beta-CoV, 

Gamma-CoV, and Delta-CoV. The alphas and betas infect mostly mammals, but these are the 2 

genera that cause human disease. They also have been isolated from many land mammals, as 

well as those that fly like bats and those that swim like beluga whales. The gammas and deltas 

mostly infect birds and have been isolated from birds across an entire spectrum of size from 

sparrows to ostriches. CoVs cause a variety of lethal diseases in mammals and birds and for 

those reasons have been well-studied due to impact on the agricultural sector where they cause 

fatal illness in herds and flocks, usually in the form of respiratory or enteric illness.

There are 7 known human coronaviruses (HCoVs), 4 of which are generally the cause of mild 

illness such as upper respiratory disease like the common cold and 3 of which are all serious 

pathogens that can cause lethal disease:

Common HCoVs (Lower Pathogenicity)

 HCoV-229E (alpha)

 HCoV-NL63 (alpha)

 HCoV-OC43 (beta)

 HCoV-HKU1 (beta)

Coronavirus Disease 2019 (COVID-19)
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

37

Other HCoVs (Higher Pathogenicity)

 SARS-CoV-1 (beta) (the cause of the 2003 SARS)

 MERS-CoV (beta) (the cause of sporadic clusters of MERS)

 SARS-CoV-2 (beta) (the cause of 2019 pandemic)

It is important to understand that the term “COVID-19” describes the illness that is caused by 

the virus SARS-CoV-2.

In terms of transmission, COVID-19 appears to have first been recognized as a human illness 

late in 2019. It is not known exactly when, how, or whether the virus arose. It is believed to 

represent a cross-species transmission from an animal reservoir, very likely bats, that may have 

involved an intermediary host like its cousins SARS-CoV-1 and MERS-CoV-2 that may have 

used the palm civet and dromedary camels as intermediary hosts. That is entirely speculative at 

this time. Even during the earlier phase of the recognized COVID-19 outbreak in the early 

weeks of January 2020, more than 35% of diagnosed persons did not report a known exposure 

to the market where the outbreak was believed to have started. It may be that this market was 

simply a location that amplified a virus that already was circulating in the community. COVID-19 

had been confirmed in nearly every province of mainland China by mid-January 2020, with the 

greatest number of cases in Hubei centered within the province’s capital in the most populous 

city of Wuhan.

The spread of COVID-19 was limited mostly to China early in the epidemic, with two large 

increases in mid-January related to a change in the Chinese case definition. As of February 25, 

2020, the daily number of new cases outside of China exceeded those within China. As of 

March 4, 2020, the number of daily deaths from COVID-19 outside China exceeded those within 

China. After a brief pause following resolution of the original outbreak in China, COVID-19 

spread rapidly worldwide beginning in early March. By that point, COVID-19 had been reported 

basically everywhere in the world except for a few island nations, Antarctica, and the 

International Space Station. Unfortunately, new diagnoses are continuing to accelerate with a 

large expansion presently occurring in the Americas. It is important to note that the most recent 

high peak in daily number was 188,000 in the last 24 hours. That number exceeded in one day 

the total 115,000 cases reported worldwide during the 6-week period that China responded to 

their outbreak. This is moving at a quick pace.

Despite the close genetic relatedness of SARS-CoV-1 and SARS-CoV-2, this new SARS-CoV-2 

differs from both SARS-CoV-1 and MERS-CoV in two very important ways. First, although the 

incubation periods are about the same, the serial interval for SARS-CoV-2 is shorter than its 

incubation period. This means that infected persons can be infectious to others and transmit the 

virus before they develop symptoms. That has not been observed for SARS-CoV-1 and MERSCoV. In fact, it has now been observed that SARS-CoV-2 infectious risk peaks in the few days 

before symptoms onset and shortly thereafter. Second, it also is now known that a substantial 

fraction of infected persons, estimated to be about 30% to 35%, never develop illness and 

remain asymptomatic. Unfortunately, these asymptomatically infected people can transmit the 

infection to others. How infectious they are to others compared to symptomatic patients is still 

being worked out.
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

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In terms of what is known about which body fluids carry and can transmit SARS-CoV-2, it is very 

clear that infections are transmitted through exposure to respiratory particles. Although viral 

RNA can be readily detected in stool, efforts to isolate the virus by culture have been 

remarkably unsuccessful with only 2 reports suggesting possible isolation of live virus and many 

reports of failed attempts. Thus, if stool is a mode of transmission, it has not yet been confirmed 

epidemiologically. Urine, blood, and other fluids to which infants might be exposed during birth 

reassuringly have not been shown to contain infectious virus. Curiously, detection of RNA has 

been confirmed in semen, but only in men during the peak of illness. After recovery, RNA no 

longer appears to be present and neither isolation of live virus nor sexual transmission of SARSCoV-2 have been reported.

People often ask how far SARS-CoV-2 can travel. There is very strong evidence that this is 

transmitted like other respiratory viruses through respiratory droplets and other particles to 

which persons are exposed in close proximity to a source patient at about 6 feet or 2 meters. 

Small aerosolized particles comprise a large fraction of what comes out of our mouths when we 

speak. Although when we shout and sing, the particles do get larger. Under highly controlled 

experimental conditions, virus has been demonstrated to exist for hours in small aerosolized 

particles. However, there is no compelling epidemiologic evidence at this time that airborne 

transmission outside of the 6-foot respiratory droplet zone is a substantial risk for spread of 

virus. Examples of transmission have not been seen across large spaces such as in restaurants 

or theaters, or infection in people whose only exposure was passing through the same space 

where an infected person had lingered but was no longer present, or transmission through air 

handling systems such as in office spaces or cruise ships. On the contrary, SARS-CoV-2 likes 

ventilation. Ventilation is one’s best friend with this virus because it substantially reduces the 

risk of infection.

Regarding how humans respond clinically to COVID-19, viral burden declines steadily after 

illness onset. Whether a sample is respiratory or stool, the quantity of viral RNA is highest at 

illness onset and decreases steadily thereafter. As viral burden declines, the ability to recover 

live virus from human samples by culture becomes more difficult. After 8-10 days, replicationcompetent virus can no longer be recovered from respiratory tract specimens based on a 

number of studies in otherwise healthy persons with mild to moderate illness. A recent study 

suggests that in severely ill and immunocompromised persons (from organ or bone marrow 

transplant), shedding of culturable virus may persist up to 20 days. Within days after symptom 

onset and as viral burden and recovery of culturable virus decline, patients begin to develop a 

serologic response to infection that includes IgM, IgG, and IgA. The IgG response includes 

neutralizing antibodies.

In addition to a time limitation of detection of live virus and infectiousness, it also is evident that 

ability to culture the virus from specimens declines with decreasing viral burden. It is remarkable 

how across a number of studies examining how long virus can be cultured, there is almost 

universally some threshold of viral burden below which virus is no longer able to be recovered, 

usually at the range of a cycle threshold (Ct) of about 30 to 35. This also depends a lot on the 

primers and polymerase chain reaction (PCR) set-up being used, which differ between 

laboratories. The point is that there is a viral burden below which there is no evidence that the 

virus can be cultured. Very interesting and novel for this virus is that it has been shown and 

widely observed that viral RNA can be detected by PCR and remain positive for weeks long 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

39

after a person has fully recovered from illness and after people are believed no longer to be 

infectious. To date, the longest persistent positive has been documented out to 12 weeks or 83 

days.

As noted earlier, this phenomenon was not observed with SARS-CoV-1 or MERS-CoV and has 

created a substantial problem for patients for whom isolation is discontinued or transmission 

precautions are removed based on a test-based strategy using PCR testing. Clinicians are 

increasingly managing patients who cannot leave the hospital, cannot return to work, or cannot 

return to other activities or a new normal of life because they are stuck in what Dr. Brooks is 

calling “persistent PCR purgatory.” He reassured everyone that CDC is actively working toward 

reviewing all of the available data and anticipate that they shortly will amend the current testbased strategy that requires 2 consecutive negatives to remove precautions.

Regarding the clinical epidemiology of this illness, early data from reports of hospitalized 

patients in different parts of China show that more than 80% developed fever during illness and 

over half developed cough, about 25% developed myalgia or arthralgia, and a small fraction in 

the 10% to 20% range had headache or diarrhea. Most people present with some acute or 

acute onset of cough and fever. Fever may be measurable at presentation, although many 

people describe a prodrome of feeling feverish but do not have a measured fever. At 

presentation, only 44% of people in one study had a measurable fever. Most will go on to 

develop a fever. There are some interesting reports of patients who presented first with 

gastrointestinal illness (GI) of abdominal discomfort and diarrhea that preceded the 

development of cough and fever by a day or two.

There is no particular set of signs, symptoms, or other related clinical findings that can reliably 

discriminate COVID-19 from other respiratory viral illnesses such as influenza at this time. One 

very interesting aspect of COVID-19 that has been of relatively high frequency are anosmia and 

dysgeusia or any other change in their sense of smell or taste. Sometimes, this has been the 

only symptom of illness. The frequencies ranged from 30% to as high as 70% in one Italian 

cohort. When present, this can be highly predictive of infection if SARS-CoV-2 is circulating in 

the community. Most people will recover spontaneously with supportive care. For those who do 

not, the typical complications are like those seem with other viral respiratory infections (e.g., 

pneumonia, respiratory failure, multi-organ system failure, and death).

Concerning the severity of illness in adults versus children from 2 large early studies in China, in 

general most (80.9%) adults who were symptomatic experienced mild illness and recovered 

without complications. However, there was a very substantial fraction who developed severe 

(13.8%) or critical (4.7%) illness. Among those with critical illness, about half died. In contrast, 

the disease was considerably less severe in children. In this cohort, less than 5% developed 

critical or severe disease during infection. A very large fraction (12.9%) were asymptomatically 

infected. It is important to note that these studies were conducted before the true frequency with 

which infections remain asymptomatic was known. It also is now known that with increasing 

age, infection is less likely to be asymptomatic, the peak viral burden that a person experiences 

is likely to be higher, and the duration of RNA shedding appears to be longer.

In terms of high-risk groups, certain underlying medical conditions (e.g., cardiovascular disease, 

diabetes, chronic respiratory disease) and advancing age increase the risk for severe illness 

and death. Once people are over 40 to 50 years of age, there is a steady increase in the case 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

40

fatality rate. The fraction of persons who die is probably related to the age structure of the 

population. The higher the average age, the larger the case fatality rate. Reassuringly, emerging 

data for immunocompromised persons seem pretty good right now. For persons with human 

immunodeficiency virus (HIV), there has not been a strong signal of risk in this country. 

However, it is expected that people with a low CD4 cell count or who are not virally suppressed 

could fair worse. Likewise, there is no definitive evidence that cancer therapy worsens 

outcomes, including immunosuppressive cancer therapy.

There are some extraordinarily unique and troublesome complications of COVID-19. The first is 

that this infection seems to cause a diffuse endotheliitis in which a viral tropism infects the 

endothelial cells that line the arteries and veins and causes inflammatory cell injury and death. 

This is seen across many different tissues in autopsy series. Second is a problem with 

hypercoagulability that has been observed in vessels of all sizes in veins and venules 

predominantly, but arteries, arterials, and capillaries as well. Autopsy examinations have 

demonstrated that clots include both those that form locally within a vessel and clots that may 

have traveled into a vein as a thromboembolism. Of particular concern are pulmonary 

thromboemboli. Two autopsy series have shown that despite aggressive anticoagulation, this 

was almost universal in 24 patients and was deemed by the pathologist as contributory or as a 

likely cause of death, but was not recognized in life. Also of interest in terms of thinking about a 

vaccine are peri- and post-infectious hyperimmune reactions. In adults, one of the most severe 

is myocarditis with ST-elevation myocardial Infarction (STEMI) without coronary artery blockage. 

It appears that the rise in enzymes is from a diffuse injury to the entire heart muscle. In children, 

multiorgan inflammatory syndrome (MIS-C) has occurred about a month after exposure or 

infection that looks somewhat like Kawasaki disease but is very distinct from it.

In closing, Dr. Brooks briefly discussed what is known about SARS-CoV-2 and influenza coinfection based on data from a study in Wuhan involving 307 patients. These data were 

collected in January and February 2020, which is typically the peak of influenza in the Northern 

Hemisphere. Diagnoses were made by assay and influenza IgM. These patients were from a 

single hospital and fell into 3 groups: SARS-CoV-2 alone (42.7%), SARS-CoV-2 + Influenza A 

(49.8%), and SARS-CoV-2 + Influenza B (7.5%). There were no significant differences in these 

3 groups in terms of age (median 50s to 60s), sex distribution (equal men and women), or 

illness severity at presentation. Although the number of co-infections with influenza B was small 

as would be expected in a typical influenza season, the patients who were co-infected with 

influenza B died at 5 to 6 times higher percentage (30.4%) that either those who had SARSCoV-2 alone (7.6%) or SARS-CoV-2 + Influenza A (5.9%). In this study, the influenza B coinfections were mostly concentrated in the first 2 weeks of January. There is the possibility that 

what is being observed here is people learning how to better manage COVID-19, with patients 

succumbing to COVID-19 rather than to the co-infection. However, if that were the case, the 

SARS-CoV-2 alone infections would have been expected to have had a somewhat higher 

percentage of death. Nevertheless, this is a very important warning to pay attention to and 

emphasizes the importance of getting an influenza vaccination.
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

41

While the current trends are disarming, this is what is known about SARS-CoV-2. First, this 

infection is nothing like influenza. Second, this virus is not like any human coronavirus seen 

before. Third, it is causing a unique, serious, and very disturbing set of clinical and 

epidemiologic problems that Dr. Brooks did not think anyone ever would have expected. Simply 

put, this is an entirely new and very bad disease. That is why a vaccine or some other form of 

effective preventive therapy is urgently needed. He wished the ACIP the very best.

Discussion Points

Dr. Romero asked whether there is now a better estimate of the percentage of children with 

asymptomatic infection and whether anything is known about their viral loads during the acute 

infectious period as compared to adults.

Dr. Brooks said that in terms of the frequency with which children appear to become infected, 

most reports seem to show that when children are equally exposed to adults, the incidence of 

infection may be somewhat lower in children. However, that has not been the case universally. 

Some studies have suggested that the frequency may be the same, but a lot of reports suggest 

that children may be less prone to infection or if infected, less likely to test positive by PCR. He 

did not know the answer to viral load or time to resolution of PCR positivity.

Dr. Drees (SHAE) noted that early on, it was only possible to obtain a COVID-19 test if 

someone tested negative for influenza. Because influenza positivity rates declined precipitously, 

some facilities stopped testing for influenza and converted to COVID-19 testing. However, it 

seems that little is known about how common co-infections are occurring in this country and 

there has been some presumption that this is uncommon.

Dr. Brooks said that part of this is a function of timing in that influenza season was beginning to 

decline as COVID-19 pandemic in this country began to grow. In terms of the Chinese data, he 

did not expect that they would see this level of co-infection. He thought perhaps China was at 

the peak of their influenza epidemic and COVID-19 stepped in, creating a lot more opportunity 

for co-infection. He did not want to discount the possibility that co-infection exists at all. CDC’s 

laboratory is currently developing a multiplex PCR test for influenza A, influenza B, and COVID19. Hopefully, that will provide a much better perspective on the frequency with which coinfection occurs and enable monitoring of clinical outcomes.

Dr. Poehling asked whether Dr. Brooks has any data from China about co-infection with 

respiratory syncytial virus (RSV).

Dr. Brooks did not have this information readily available but added this to his follow-up list.
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

42

Immune Responses to SARS-CoV-2 Infections

Natalie J. Thornburg, PhD

Respiratory Virus Immunology Team Lead

ACIP SARS-CoV-2 Working Group

National Center for Immunization and Respiratory Diseases 

Centers for Disease Control and Prevention

Dr. Thornburg presented on what is known about immunity to coronaviruses in general, what is 

known so far about SARS-CoV-2 immunity, testing for immune responses, and updates on 

recently published data on severity of disease versus antibody response and antibody kinetics.

The various types of coronaviruses can be divided broadly into common coronaviruses that 

cause colds (229E, NL63, OC43, HKU1) and uncommon coronaviruses (SARS-1 and MERS). 

SARS-1 is no longer circulating, while MERS is circulating in a very limited form.

It is difficult to extrapolate what is known about SARS-1 and MERS to immunity about SARSCoV-2 because they are so rare. It may be necessary to take note on what is known about the 

common CoVs, although it is not a lot. It is known that there is protection in common CoV 

infections, but it can be transient and waning serum neutralizing antibodies may contribute to 

susceptibility to reinfection. A study was conducted on a 229E human challenge model in the 

late 1980s and early 1990s by Callow et al. In this study, 15 volunteers were inoculated with 

HCoV-229E and challenged. The 10 volunteers with lower antibody titers became infected and 

only 8 of them developed colds. Presumably, these were all adult volunteers, so they probably 

had baseline serum antibody titers and cellular immunity against the virus. On re-challenge a 

year later, 9 of the 10 individuals who became infected became re-infected as assayed by virus 

shedding. However, none of them developed a cold. It seems like even if they did not have 

sterilizing immunity, many of them had some immunity that protected against symptoms. A 

household transmission study was published by Kiyuka et al in 2018. This study found that 2.5% 

of household members had an NL-63 infection. Most household subjects had only one infection 

in the 6-month study. The investigators looked for repeat infections of all of the common 

coronaviruses and found repeat infections with NL-63 (21%), OC43 (5.7%), and 229E (4%). 

Those were all more than 90 days apart, so there was at least short-term protection against 

reinfection. A minority of the repeat infections exhibited higher viral titers on the second infection 

(41% NL-63, 31% OC43, and 1% 229E), so most of the second infections exhibited lower viral 

titers.

It has been a few months now and at least short-term immunity against SARS-CoV-2 has been 

characterized in terms of whether SARS-CoV-2 resembles common coronavirus immunity. It 

has been determined thus far that most COVID-19 patients mount IgG and IgM responses

to the virus, many CoVID-19 patients mount neutralizing antibody responses, and the 

magnitude of the antibody response correlates to disease severity. In general, the more severe 

the infection the stronger the antibody response. It remains unknown whether COVID-19 

patients are susceptible to reinfection, whether antibodies are a correlate of immunity and of 

what quality if so (isotype, antigenic region, neutralizing), if there is a threshold of protection, 

and how long serum antibodies will last.
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

43

Two broad categories of antibody assays can be used to detect antibodies, binding and 

functional. The binding assays used tend to test for antibodies against spike proteins or nucleic 

acid proteins. Three different versions of the spike protein are used in assays. The spike is the 

target for neutralizing antibodies. Nucleocapsid is abundant during viral replication. Assays can 

test for total Ig, Pan Ig that detects any immunoglobulin, IgG, IgM, and/or IgA.

The spike antigen is a trimer. It is a massive protein that is divided into the S1 region and the S2 

region. It has a receptor binding domain (RBD) and the S2 domain. It is metastable and exists in 

a pre-fusion and post-fusion conformation. Three forms of spikes comprise a single protomer on 

the virion. Three versions of the protein are used in antibody assays (RBD, S1, one protomer

of ectodomain or S2P along with the S2 domain). A variant has emerged as the more dominant 

circulating variant that has a coding mutation in the spike protein at residue 614. The D614 

residue is right at the S1 and S2 interface. It is away from the RBD but is somewhat near the 

fusion machinery. Thus far, individuals who have tested the ability of serum to neutralize this 

new variant have not found differences between the original circulating variant and the 614G 

variant. However, it could in theory escape some antibody responses.

Nucleocapsid protein is also a target for antibodies and is used in antibody tests. It is not the 

target for neutralizing antibodies. However, it is easy to produce large quantities and it is 

abundantly expressed during early infection. Therefore, it is a very sensitive assay. However, it 

is unlikely a target for neutralizing antibodies. Dr. Thornburg shared a table of enzyme-linked 

immunosorbent assays (ELISA) and chemiluminescent microparticle immunoassay (CMIA) with 

Food and Drug Administration (FDA) and Emergency Use Authorization (EUA) authorization, 

showing the manufacturer, isotype, antigen, % positive agreement, % negative agreement and 

number of specimens used to validate the assay as of 6/18/20.

In addition to the binding assays that are used to detect any antibodies that bind, there are 

several ways to detect functional antibodies. This is a general list of the kinds of neutralization 

assays that laboratories and clinics are using to detect antibodies that neutralize the virus:

 Plaque reduction neutralization titer, which is a classical test for serum that is mixed with 

virus to determine how much serum is needed to stop production of plaque 

 Clinical isolate microneutralization, which uses isolates made from patients to determine 

how much serum is needed to completely block virus-induced cytopathic effect

 Infectious clone reporter microneutralization, which are used in containment because they 

are fully infectious viruses that have a reporter gene inserted into the genome so that there 

is a fluorescent out read

 Focus reduction assay, which is an immunostain for a viral protein that is somewhat faster 

than a plaque reduction assay

 Pseudoviruses, which are being used widely in vaccine trials now because they can be done 

at lower containment in Biosafety Level 2 (BSL-2) laboratories, involve putting the spike 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

44

protein on the backbone of another virus and that usually has a reporter gene, are faster 

and easier to do, but can be more sensitive than live virus neuralization assays

In terms of what is known about antibody responses thus far, more severe patients exhibit more 

robust and faster antibody responses1

. A majority of hospitalized COVID-19 patients develop 

neutralizing antibody responses2

. Thirty percent of patients with mild infection have low 

neutralizing antibody titers of less than 500 at hospital discharge. No major changes were 

observed in the neutralizing antibody responses between discharge and revisit among 47 

patients3

. Older patients had higher neutralizing antibody titers4 [1To et al. The Lancet. 20: 565-

574; 2

Suthar et al. Cell Reports Medicine. 2020 Jun 8; and 

3, 4 https://www.medrxiv.org/content/10.1101/2020.03.30.20047365v2].

Most of what is known about SARS-CoV-2 immunology is from hospitalized patients, but what 

about milder infections? A study was conducted of sailors on the USS Teddy Roosevelt (USS 

TR) in which a microneutralization was used that required full neutralization of the virus, so it is 

a high bar. This study found that 41% of these young, healthy adults who had antibody 

responses did not have detectable neutralization titers1

. There was a recent study looking at 

asymptomatic and symptomatic patients at the acute and convalescent phases. The 

convalescent timepoint was at 8 weeks post-discharge. This study found a decay in the acute 

and convalescent timepoints in the asymptomatic and symptomatic patients in binding 

antibodies and neutralizing antibodies. They were mostly still above the limit of detection of 

binding antibodies, but neutralization titers did drop below the 50% threshold in a large number 

of the symptomatic patients2

 [1Payne et al. MMWR. 69: 714-721; 2Long et al. Nature Medicine. 

18 JUN 2020].

In conclusion, it is known that most SARS-CoV-2 patients mount serum antibody responses and 

even mild cases of SARS-CoV-2 can result in development of antibodies. The magnitude of 

antibody response roughly correlates with severity, which is consistent with what is known about 

other coronavirus infections. A portion of individuals with antibody responses may not develop

serum neutralizing antibody responses. By 8 weeks after discharge, a portion of patients have 

dropped below the 50% inhibition neutralization threshold.

Open Discussion

Dr. Frey inquired as to whether there is any reason to believe that there is an antibodydependent enhancement phenomenon that is occurring and if so, what proteins would be the 

culprits. She also wondered whether there is any evidence that some of the common 

coronaviruses such as OC43 were once very virulent and that SARS-CoV-2 might go that same 

route.

Dr. Thornburg did not think there were any data yet to suggest antibody-dependent 

enhancement of infection. There has not been any evidence 6 months in that anyone has had 

an antibody response who then went on to have a more severe infection if they got a second 

infection. While it is still early, there is no evidence of this yet. It is likely that SARS-CoV-2 

immunity will be similar to common coronavirus infections. She did not recall historically what 

the emergence of common coronaviruses looked like but did not think it was as severe as the 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

45

emergence of SARS-CoV-2. She suspected that when they entered the population, they were 

as infectious.

Dr. Lee wondered whether there were any historical data on whether the antibody responses 

levels for the common coronaviruses differed by age or risk conditions.

Dr. Thornburg indicated that they do not have those types of data because they are common. 

Common coronaviruses are like a lot of other upper respiratory infections in that those are 

mostly diseases of childhood, which most people acquire by the time they are 2 to 5 years of 

age. This is complicated by the fact that people have memory B-cells and T-cells against the 

virus. 

US COVID-19 Epidemiology

Sara Oliver MD, MSPH

National Center for Immunization and Respiratory Diseases 

Centers for Disease Control and Prevention

Dr. Oliver reported on US COVID-19 epidemiology among healthcare personnel (HCP), longterm care facility (LTCF) residents, children, pregnant women, and people in congregate 

settings as well as serology. As of June 23, 2020, a total of 2.30 million COVID-19 cases have 

been reported to CDC with 120,000 deaths.

A Morbidity and Mortality Weekly Report (MMWR) was recently published describing COVID-19 

case surveillance through May 30, 2020. Through that time, over 1.7 million cases were 

reported to CDC. Hospitalizations were 6 times higher among patients with reported underlying 

conditions, and deaths were 12 times higher. Several clinical outcomes varied by sex. Males 

were hospitalized, admitted to the intensive care unit (ICU), and died at a slightly higher 

percentage compared to females. In terms of cases by date of report to CDC, the 7-day moving 

average peaked on April 12, 2020. While there has been a decline since then, the 7-day moving 

average indicates ongoing community transmission. The 7-day moving average of deaths 

peaked on April 21, 2020.

In terms of the number of specimens tested for SARS-CoV-2 using a molecular assay and 

reported to CDC by public health laboratories, the overall percent positive was 5.5% for the past 

week. The number of specimens testing positive has decreased since the initial increases in 

April. While the number of specimens from children tested as low represented less than 5% of 

specimens testing, the percentage testing positive in this age group was higher than in the adult 

age groups. Regarding the specimens tested and percent positive among commercial 

laboratories reported to CDC, the overall percent positive was 6.7%. The percentage of 

laboratory specimens testing positive was low but increased slightly in the past 2 weeks of 

reporting.

Visits to emergency departments (EDs) are monitored through the National Syndromic 

Surveillance Program (NSSP). To track trends, visits for influenza-like illness (ILI) or COVID-like 

illness (CLI) are monitored in a subset of EDs in 47 states. In the week ending June 13, 2020, 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

46

1.7% of ED visits captured in NSSP were due to CLI and 0.6% were due to ILI. Levels of both 

ILI and CLI increased in late March 2020 and then declined.

The National Center for Health Statistics (NCHS) collects death certificate data from vital 

statistics offices for all US deaths. Through the week ending June 13, 2020, 7.1% of all deaths 

were due to pneumonia, influenza, or COVID-19. This was the 8th week of decline; however, the 

percentage remained above the epidemic threshold.

The COVID-19-Associated Hospitalization Network (COVID-NET) conducts population-based 

surveillance for laboratory-confirmed COVID-19-associated hospitalizations in select counties in 

14 states. This covers approximately 10% of the US population. A patient must be a resident of 

the surveillance area and have a positive SARS-CoV-2 test within 14 days prior to or during 

hospitalization. Charts are reviewed by trained surveillance officers. As of June 13, 2020, the 

overall hospitalization rate was 94.5/100,000 population with the highest rates in people ≥65

years of age at 287/100,000. COVID-19-associated hospitalization rates by race and ethnicity 

are calculated using hospitalized COVID-NET cases with known race and ethnicity for the 

numerator and bridged race population estimates for the denominator.

The age-adjusted hospitalization rates by race and ethnicity per 100,000 were 221.2 per 

100,000 among Non-Hispanic American Indian or Alaska Native (AI/AN) persons, a rate 

approximately 5.5 times that of non-Hispanic White persons; 178.1 among Non-Hispanic Black

persons, a rate approximately 4.5 times that of non-Hispanic White persons; 160.7 among

Hispanic or Latino persons, a rate approximately 4 times that of non-Hispanic White persons; 

48.4 among Non-Hispanic Asian or Pacific Islander persons, a rate approximately 1.2 times that 

of non-Hispanic White persons; and 40.1 among Non-Hispanic White persons. Overall, 91% of 

hospitalized adults had at least one reported underlying medical condition. The most commonly 

reported were hypertension (56%); obesity (49%); metabolic disease, including diabetes (42%); 

and cardiovascular disease (33%). Of hospitalized children, 53% had at least one reported 

underlying medical condition. The most commonly reported condition among children was 

obesity (38%).

An MMWR was published on June 17, 2020 that evaluated the characteristics associated with 

hospitalization among patients with COVID-19 from 6 metropolitan Atlanta hospitals and clinics. 

There were 220 hospitalized and 311 non-hospitalized included. Several factors were 

independently associated with hospitalization, including age ≥65 years, Black race, having 

diabetes mellitus (DM), lack of insurance, male sex, smoking, and obesity.

Turning to COVID-19 epidemiology amongst HCP, an MMWR in April 2020 described the 

characteristics of HCP with COVID-19. Among the cases reported at that time, 9200 (19%) were 

identified as a HCP. Among 1423 HCP patients who reported contact with a laboratoryconfirmed COVID-19 patient in either a healthcare, household, or community setting, 780 (55%)

reported having such contact only in health care setting in the last 14 days. Most HCP were not 

hospitalized; however, severe outcomes occurred across all age groups, including 27 (0.6% of 

4407) deaths. CDC reports and routinely updates cases and deaths among HCP on the CDC 

website. As of June 23, 2020, there have been 83,673 cases and 464 deaths among HCP.
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

47

Dr. Oliver indicated that for each of the at-risk populations, she would highlight next steps and 

ongoing research to learn more. As data are available for each of these projects, the results will 

be shared with ACIP to inform future policy decisions. There are several projects ongoing 

related to HCP. The first is Project COVID Evaluation of Risk in Emergency Departments 

(Project COVERED), which is a prospective cohort study of 1600 HCP working in US EDs. The 

objectives are to: 1) estimate attributable risk of occupational acquisition of COVID-19 infection 

for emergency physicians and nurses; 2) estimate attributable risk of occupational acquisition of 

COVID-19 infection related to endotracheal intubation; 3) identify risk factors associated with 

SARS-CoV-2 transmission during intubation; and 4) determine the prevalence of symptomatic 

and asymptomatic COVID-19 infections occurring in ED HCPs. Serial symptom questionnaires, 

serology, and PCR will be collected over a 12-week period.

There are also HCP projects through the Emerging Infections Program (EIP), which is a network 

of 10 state health departments and local public health and academic partners. The projects 

include surveillance for, and interviews of, HCP cases compared to HCP non-cases. As of June 

12, 2020, over 1000 cases had been reported and 425 interviews were conducted. Data will be 

shared with ACIP as soon as it is available.

There are two additional HCP studies, the Arizona Healthcare, Emergency Response and Other 

Essential Workers Surveillance Study (AZ HEROES) and Research on the Epidemiology of 

COVID-19 in Emergency Response and Healthcare Personnel (RECOVER). Both studies are 

primarily cohort studies over 12 months with repeat PCR and serology collected among HCP, 

first responders, and essential workers to determine the incidence of symptomatic and 

asymptomatic infections among these individuals.

Moving to LTCFs residents, there have been several published descriptions of a facility in King 

County, Washington. Through March 18, 2020, there were 167 confirmed COVID-19 cases 

associated with that facility. Of these, 101 were residents, 50 were staff/HCP, and 16 were 

visitors. Overall, 86% of residents were confirmed positive and 34% died. This report, as well as 

experience at other facilities, show that once COVID-19 has been introduced into a LTCF, it has 

the potential to result in high attack rates among residents, staff members, and visitors. Many 

areas contribute to the vulnerability of LTCFs, including inadequate familiarity with and 

inadequate supplies of personal protective equipment (PPE), high prevalence of underlying 

conditions, atypical presentations in the elderly, and the fact that many facilities share staff and 

patients. This was highlighted in a journal article where numerous facilities in King County 

shared either staff or patients with the initial facility, potentially introducing COVID-19 into those 

facilities as well [McMichael TM, et al. NEJM 2020].

The Centers for Medicare and Medicaid Services (CMS) released a rule on April 30, 2020 

requiring all nursing homes certified by CMS to report data through CDC’s National Healthcare 

Safety Network (NHSN). As of the week ending June 7, 2020, almost 15,000 nursing homes are 

reporting through this COVID-19 module. These facilities reported over 107,000 confirmed 

COVID-19 cases; over 71,000 suspect cases; and almost 30,000 deaths in residents. CMS 

began publicly reporting data from nursing homes on June 4, 2020. CDC also tracks what states 

report publicly. These numbers include a broader range of LTCFs beyond nursing homes, such 

as assisted living facilities. As of June 11, 2020, there were at least 245,605 cumulative 

confirmed or probable COVID-19 cases in residents and staff from 10,708 LTCFs across 51 US 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

48

states and territories based on state health department websites and other publicly available 

information. Information collected through the COVID-19 modules for LTCF will be used to 

strengthen COVID-19 surveillance locally and nationally; monitor trends in infection rates; and 

help local, state, and federal health authorities get help to nursing homes faster.

Focusing next on epidemiology among children, children may have different or minimal 

symptoms compared to adults such as abdominal pain or GI symptoms1

. They also may be 

more likely to be asymptomatic1,2. In addition, there is limited information to date regarding the 

role children play in transmission. Early in the outbreak in China while children were still in 

classes, school-aged children had the largest number of close contacts of any age3

. The 

efficiency of spread in schools by children is unknown. Existing data are reassuring, but are 

limited4-6 [1

MMWR April 10, 2020; 2Dong et al. Pediatrics. June 2020; 3Zhang et al. Science April 

2020; 4Heavey et al. Eurosurveillance May 2020; 5Johansen et al. Eurosurveillance May 2020; 

and 6

COVID-19 in schools- the experience in NSW April 2020 Report].

One of the more concerning aspects of the COVID-19 pandemic has been the severe 

inflammatory disease seem among children. It was initially called Pediatric Inflammatory 

Multisystem Syndrome (PIMS) and initially was described in Europe. It presented with a 

Kawasaki-like disease and cardiac involvement. The epidemic curve peaked 4 to 5 weeks after 

the peak of the COVID-19 epidemic in France, which could suggest a post-infectious process 

[Belot et al. Euro Surveill 2020].

A report from England described 58 children with fever and laboratory evidence of inflammation. 

Among them, 15/58 (26%) children had a positive SARS-CoV-2 PCR, 40/46 (87%) children had 

a positive SARS-CoV-2 IgG, and 45/58 (78%) overall had evidence of current or prior SARSCoV-2 infection. All patients presented with persistent fever (3-19 days), 31/58 (53%) had 

abdominal pain, and 30/58 (52%) had rash. In addition, 29 (50%) children developed shock and 

myocardial dysfunction; 8 (14%) children developed coronary artery dilation or aneurysm; and 2 

(3%) children required extracorporeal membrane oxygenation (ECMO) [Whittaker et al. JAMA

2020].

A notice through the Health Alert Network (HAN) was released by CDC on May 14, 2020 

establishing a case definition for Multisystem Inflammatory Syndrome in Children (MIS-C) in the 

US. This case definition includes the following:

• Fever > 38.0°C

AND

• Laboratory evidence of inflammation

AND

• Evidence of clinically severe hospitalized illness with multisystem (≥2) organ involvement 

(cardiac, renal, respiratory, hematologic, gastrointestinal, dermatologic or neurological)

AND

• One of the following:

1. SARS-CoV-2 positive PCR test

2. SARS-CoV-2 positive antibody test

3. SARS-CoV-2 negative PCR and antibody tests but with identified COVID exposure 

within the four weeks prior to the onset of symptoms
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

49

Information on MIS-C in the US has been collected through the Overcoming COVID-19 Study 

coordinated by Boston Children’s Hospital and funded by CDC. There were 213 MIS-C cases 

enrolled at 53 participating health centers in 26 states. Most were previously healthy, with a 

median age of 8.4 years. Among these children, 73% were PCR or antibody positive at 

admission. Cardiovascular involvement was prominent at 81%, 50% had an elevated troponin,

38% had an ejection fraction <55%, 50% required vasopressor support, and ~9% had coronary 

aneurysms. It is known from experience with Kawasaki disease that coronary aneurysm has 

long-term implications when diagnosed in children.

There are several surveillance systems CDC can use to monitor MIS-C. First, CDC 

recommends that HCP report suspect cases of MIS-C to local, state, or territorial health 

departments. These health departments can then report cases to the National Notifiable 

Diseases Surveillance System (NNDSS) for case counts and case report forms are submitted

using other MIS-C specific surveillance systems. Cases also can be assessed through the New 

Vaccine Surveillance Network (NVSN), which consists of 7 pediatric medical centers conducing 

active surveillance for acute respiratory and gastrointestinal illness, and COVID-NET described 

previously.

In terms of pregnant women, there can be physiologic changes in pregnancy that may increase 

the risk of severe illness (increased heart rate and oxygen consumption, decreased lung 

capacity, shift away from cell-mediated immunity)1

, and severe disease has been associated 

with other viral respiratory infections in pregnant women1-4. However, initial reports have been 

unclear regarding COVID-19’s impact on pregnant women. Recent studies are helping to define 

this better [1

Ramsey PS et al. Pneumonia in pregnancy. Obstet Gynecol Clin North Am 2001; 

2

Galang RR et al. Severe Coronavirus Infections in Pregnancy: A Systematic Review [online 

ahead of print, 2020 Jun 16]. Obstet Gynecol. 2020; 3

Mertz D et al. Populations at risk for 

severe or complicated influenza illness: systematic review and meta-analysis. BMJ 2013; and 

4

Mosby LG et al. 2009 pandemic influenza A (H1N1) in pregnancy: a systematic review of the 

literature. Am J Obstet Gynecol 201].

A recently published prospective cohort study was conducted from mid-March to mid-April 2020 

at 5 medical centers in New York City (NYC). There were 241 women with a positive SARSCoV-2 test. Who was tested varied by medical center and over the timeframe due to test 

availability, evolving epidemiology, and hospital policies. Among the 241 women in the study, 

89% were admitted for obstetric indications and the remainder for GI or ILI, 148 (61%) were 

asymptomatic at the time of admission, and 46 developed COVID-19 symptoms during 

hospitalization. A body mass index (BMI) of ≥30 was associated with COVID-19 severity. 

Insurance type, age, race and ethnicity, and underlying medical conditions were not associated 

with COVID-19 severity. There were 236 liveborn neonates with documented SARS-CoV-2 test 

results, of whom 230 (98%) tested negative. The preterm (<37 weeks gestation) birth rate in this 

cohort at 14.6% is higher than in the general population at 10.2%*, with a statistically significant 

linear trend between COVID-19 maternal severity and the risk of preterm birth [Khoury R et al. 

Obstet Gynecol 2020; *Martin J et al. Births in the United States, 2018. National Center for 

Health Statistics]. 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

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Turning to information from an MMWR scheduled to be released later in the week, from January 

22, 2020-June 7, 2020 there were over 300,000 cases of laboratory-confirmed SARS-CoV-2 

infection in women of reproductive age (WRA) defined as 15 through 44 years of age and 

reported to CDC through COVID-19 surveillance. Of those, 28% (91,412) had available data on 

pregnancy status. Of them, 8207 (9%) were reported as pregnant. This percentage may be 

affected by more frequent healthcare encounters among pregnant women that increased 

opportunities to receive SARS-CoV-2 testing, missing pregnancy status, or increased screening

among pregnant women. A number of inpatient obstetric healthcare facilities have implemented 

universal screening and testing policies for pregnant women upon admission. Among pregnant 

women, 31.5% were reported as hospitalized compared with 5.8% of non-pregnant women. 

After adjusting for age, the presence of underlying medical conditions, and race and ethnicity 

pregnant women were significantly more likely to be hospitalized with an adjusted risk ratio of 

5.4. Pregnant women were 50% more likely to be admitted to the ICU and 70% more likely to 

receive mechanical ventilation. Among pregnant women, 16 deaths were reported in a similar 

portion to non-pregnant women.

There are challenges in interpretation of hospitalization as an outcome for severe COVID-19 

illness in pregnant women as data are not available to distinguish hospitalization for COVID-19 

from hospitalization admission for pregnancy-related conditions. Therefore, differences in 

hospitalization by pregnancy status may reflect a lower threshold for admitting pregnant patients 

or the universal screening of women admitted to a labor and delivery unit. In an analysis of 

outcomes among pregnant versus non-pregnant women hospitalized with lab-confirmed 

COVID-19 from COVID-NET, the risk of ICU and mechanical ventilation was lower among 

pregnant compared to non-pregnant women, and there was no statistically significant 

differences in the risk of in-hospital death. While the reason for admission is not specified, it is 

possible that non-pregnant women were predominately admitted for medical illness, whereas 

pregnant women were admitted for medical illness or labor and delivery. Pregnant women 

admitted solely for labor and delivery are likely healthier than pregnant or non-pregnant women 

admitted for medical illness.

In summary, this new report includes the largest US cohort of pregnant women with laboratoryconfirmed SARS-CoV-2 infection. More complete data are needed to assess whether SARSCoV-2 infection in pregnancy is associated with adverse pregnancy or neonatal outcomes. The 

results from this study suggest an increased risk of ICU admission and mechanical ventilation, 

which are distinct proxies for severity, in pregnant women compared to nonpregnant women. 

However, the absolute risk of these clinical interventions is still very low in this population.

In terms of next steps regarding pregnant women, cohort studies, including retrospective 

electronic cohorts and prospective community cohorts, will assess incidence and 

seroprevalence of SARS-CoV-2 in pregnancy and severity of disease. Supplemental 

surveillance is being implemented to collect additional data on pregnancy and neonatal 

outcomes through the Surveillance for Emerging Threats to Mothers and Babies Network (SETNET), and teams are leveraging existing pregnancy surveillance systems such as the 

Pregnancy Risk Assessment and Monitoring System (PRAMS) and COVID-NET.
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

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Regarding COVID-19 epidemiology among people in congregate settings, 115 meat or poultry 

processing plants in 19 states reported COVID-19 cases to CDC in April 2020. COVID-19 was 

diagnosed in 4913 (~3%) workers. By state, this ranged from 0.6% to 18.2% of workers. There 

were 20 deaths reported that were related to COVID-191

. In April, there were 420 correctional or 

detention facilities with at least 1 case of COVID-19 from 32 state and territorial health 

department jurisdictions, with nearly 5000 cases among incarcerated persons and 2778 staff. 

There were 88 COVID-19 related deaths reported among incarcerated persons, 15 of which 

were among staff2

. There were nearly 1200 residents and over 300 staff members tested in 19 

homeless shelters in 4 US cities from late March 27, 2020 to mid-April 15, 2020. Homelessness 

poses multiple challenges that can amplify spread of COVID-19. Among shelters associated 

with a cluster (meaning 2 or more residents tested positive for COVID-19 in the prior 14 days), 

the percent of residents who tested positive ranged from 17% to 66%. In shelters not associated 

with a cluster, there were much lower rates of infection at 4% to 5%3 [

1

MMWR May 1, 2020; 

2

MMWR May 6, 2020; and 3MMWR April 22, 2020].

For a brief overview of some ongoing serology studies, there are numerous seroprevalence 

surveys underway or about to begin. These include large-scale geographic seroprevalence 

surveys to estimate the number of people previously infected with SARS-CoV-2 and not 

included in official case counts. These include specimens from commercial laboratories and 

blood donations. There also are community-level seroprevalence surveys that cover smaller 

areas such that participants can be systematically selected. There also are special populations 

seroprevalence surveys that are meant to answer questions about specific populations, such as 

HCP or pregnant women.

In summary, approximately 2 million cases of COVID-19 were diagnosed in the US through 

June 2020. Multiple sub-populations appear to have an increased risk, including older

adults, HCP, individuals at LTCF and other congregate settings, and those with underlying 

medical conditions. Many projects are ongoing to better define characteristics of SARS-CoV-2 

infections, which will be shared with ACIP once the results are available.

Open Discussion

Dr. Romero noted that Dr. Oliver presented data through May 30, 2020. However, there was an 

increase in the number of cases reported in the last few weeks. He requested further 

information about those cases and the number of states with increases in cases.

Dr. Oliver clarified that the MMWR with the 7-day average was through May 30, 2020. The rest 

of the data were through June 13, 2020. CDC publishes a COVIDView report every Friday that 

includes the previous week’s surveillance summary of US COVID-19 activity. These data are 

publicly available on the website.

Dr. Bell wondered whether Dr. Oliver could reflect on plans moving forward for sensitive 

surveillance at multiple levels. It seems like having a sensitive surveillance system is going to be 

very important for control efforts, especially in the contact of influenza season.
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

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Dr. Oliver indicated that there have been multiple efforts over the summer to strengthen 

surveillance systems across the US, leveraging existing influenza surveillance systems and 

diagnostics as well.

Dr. Szilagyi noted that there are some anecdotal reports that there is a major difference in the 

prevalence of MIS-C in the US on the East Coast versus the West Coast and asked Dr. Oliver 

to comment on that. Regarding the large study on pregnant women and hospitalizations and 

ICU admissions, there is clearly a strong hospitalization bias. Many hospitals test for COVID-19 

immediately upon hospitalization. The ICU and mechanical ventilation data for pregnant women 

were concerning, and he wondered whether Dr. Oliver had any additional information about the 

stage of pregnancy among the women with COVID-19 in the ICU.

Regarding MIS-C, Dr. Oliver indicated that there are ongoing projects assessing incidence and 

numbers across the US and by region. As it is a relatively rare outcome at this point, CDC is 

collecting data and will continue to report the results as data become available. In terms of 

pregnant women, the upcoming MMWR to be published on June 24, 2020 will have additional 

data that Dr. Oliver was not able to present due to time. This includes some additional analyses. 

She did not know whether it was broken down by trimester of pregnancy. Given that many of 

them women were admitted for delivery, the data are probably skewed toward later pregnancy. 

Surveillance systems are being enhanced throughout the US to collect additional data on 

pregnant women. 

In reference to the previous question asking about recent increases, CDC is reporting daily case 

counts, and increase has been seen an increase in cases that have been reported in the US 

over the previous couple of weeks across the US.

Dr. Lee noted that one curious finding that stood out for her was that the proportion of positive 

tests was higher among children, which was a surprise given all that had been seen and heard 

to date regarding asymptomatic cases. She asked whether tests are done in symptomatic and 

asymptomatic children, and whether Dr. Oliver thinks there may be a reason that there is an 

increasing trend for test-positive children.

Dr. Oliver responded that the current laboratory systems through CDC do not have the ability to 

distinguish between symptomatic and asymptomatic infections, though they hope to enhance 

that moving forward. It is less that they have been increasing in recent weeks and more that 

they have held steady as other things have declined. They think this is likely multifactorial, but it 

likely just represents that they are a very unique population. Given that they have had such a 

small proportion of tests done, it also could be that the pre-test probability of who is being 

testing is somewhat higher. They are looking into this to try to figure it out across the US.
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

53

Maintaining and Strengthening Childhood Vaccination During the COVID-19 Pandemic

Melinda Wharton, MD, MPH

Director, Immunization Services Division

National Center for Immunization and Respiratory Diseases

Centers for Disease Control and Prevention

Dr. Wharton provided an update on CDC’s work on routine childhood vaccination during the 

COVID-19 pandemic, as well as the planning being done for the upcoming influenza season.

In mid-March 2020, there was a precipitous drop in ambulatory care visits of nearly 70% as 

stay-at-home orders were issued around the US. Some recovery was seen in early May 2020, 

although the number of visits remained well below baseline. Pediatrics was among the hardest 

hit specialties, with a 62% reduction in pediatric outpatient visits by the week of April 5, 2020. 

There was some improvement by the week of May 10, 2020 in terms of increases in outpatient 

visits across all pediatric age groups, with the least reduction seen in visits for children under 2 

years of age and the most for children 3 to 5 years of age [Ateev, M. et al., To the Point (blog), 

Commonwealth Fund, updated May 19, 2020].

The Vaccines for Children (VFC) program provides federally purchased vaccines for eligible 

children in the US. In order to assess the impact that these reductions in outpatient visits on 

childhood vaccination, weekly VFC vaccine orders were assessed for all childhood vaccines 

other than influenza vaccines in 2020 compared to the comparable week in 2019. This 

assessment showed a dramatic reduction in vaccine orders beginning in mid-March 2020 and 

extending into early May 2020. A similar pattern was observed for measles-containing vaccines, 

but with much greater reductions. Also during this time, many medical practices were under 

severe stress as patients were not being seen, staff may have been furloughed, and some 

practices closed temporarily or permanently.

With partners, CDC has undertaken a number of activities to support recovery of routine 

childhood vaccination. In addition to monitoring service delivery, CDC has developed guidance 

on routine vaccination, the importance of well-child visits, and safe vaccine delivery. The agency 

has encouraged state immunization programs and healthcare practices to encourage catch-up 

vaccinations through reminder/recall systems. With state partners, CDC is identifying gaps in 

the VFC provider network and through the budget process, planning for a potential increase in 

the VFC-eligible population. CDC has worked with partners to identify policy interventions to 

support healthcare providers. In terms of communications, CDC has supported efforts to 

communicate about the importance of well-child visits and routine childhood vaccination to 

parents, providers, and partners as well as efforts to raise awareness about the VFC program 

for families who may be newly eligible. Finally, it is critical to address catch-up now to allow 

moving on to back-to-school vaccination activities during the summer and influenza vaccination 

in the fall.

Initial support for healthcare providers through the Provider Relief Fund was directed to 

providers participating in Medicare. Since June 9, 2020, providers participating in Medicaid and 

the Children’s Health Insurance Program (CHIP) have been included. CDC has continued to 

promote catch-up vaccination through dissemination of information on best practices for 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

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reminder/recall, including refocusing of the Immunization Quality Improvement for Providers 

(IQIP) program activities on catch-up vaccination. CDC also has disseminated guidance to 

providers on the safe delivery of vaccines during the COVID-19 pandemic.

The “CDC Interim Guidance for Immunization Services During COVID-19 Pandemic” identifies 

vaccination as an essential medical service for all children and adolescents that ideally should 

be delivered in the medical home. All due or overdue vaccines should be administered 

according to the routine immunization schedule during the same visit, and strategies to catch-up 

patients on vaccines they missed should be implemented starting with the youngest children 

and extending through adolescence. The guidance also addresses safe delivery of vaccines, 

including the use of PPE and physical distancing. CDC’s communication efforts are focused on 

encouraging parents to return for well-child visits, encouraging the use of reminder/recall 

systems to help children get up to date as quickly as possible, and encouraging providers to 

share with families the safety protocols put in place to ensure patients can be safely seen in a 

clinic to be vaccinated.

CDC also has been working with partners to promote awareness of the VFC program among 

parents. Prior to the COVID-19 pandemic, approximately 50% of US children were eligible to

receive free vaccines through VFC. More may be eligible now due to parents’ loss of insurance 

or increased economic hardship. These families who have newly eligible children may not know 

about the VFC program. CDC appreciates the support of partners and providers to increase 

awareness about this critically important program. In addition, CDC has created resources for 

communicating with parents about routine vaccination during the COVID-19 pandemic. The 

American Academy of Pediatrics (AAP) has developed a highly sharable social media campaign 

directed at parents using the hashtag #CallYourPediatrician. 

CDC was pleased to see improvement in the weekly vaccine orders from the VFC program in 

May 2020. In terms of individual vaccines, the recovery is greater for vaccines given to infants 

such as Haemophilus influenzae type b (Hib) and less for pre-teens and adolescents like human 

papillomavirus (HPV). This shows that there is still room for improvement, although things are 

moving in the right direction.

School vaccination requirements provide a critical checkpoint for children’s vaccination status. 

Many children need to receive vaccines during the summer to stay up-to-date and comply with

school vaccination requirements. It is very important that back-to-school vaccine clinics take

place this summer to provide children an opportunity for vaccination. In the event that COVID-19 

circulation disrupts the back-to-school vaccination effort, CDC encourages jurisdictions if 

possible to allow additional time for compliance rather than suspending school requirements 

completely through some sort of emergency action or creating a situation in which families feel 

like they need to seek exemptions.

Moving on to planning for the upcoming 2020-2021 influenza season, the influenza season that 

just concluded was characterized by an initial wave that was predominantly influenza B followed 

by a later wave of influenza A(H1N1). As of June 13, 2020, a total of 185 pediatric deaths that 

were associated with laboratory-confirmed influenza had been reported to CDC. CDC estimates 

that in the 2019-2020 season, there were millions of illnesses and medical visits, hundreds of 

thousands of hospitalizations, and tens of thousands of deaths due to influenza.
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

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Because it is anticipated that SARS-CoV-2 will continue to circulate into the fall, influenza 

vaccination will be an important strategy to decrease stress on the healthcare system by 

decreasing doctor visits and hospitalizations, as well as decreasing the number of people who 

will need diagnostic testing. Given the risk groups who have been identified for COVID-19, 

influenza vaccination will be particularly important for staff and residents of LTCF, adults with 

underlying illnesses, African Americans, and adults who are part of critical infrastructure. There 

are longstanding disparities by race and ethnicity in vaccine coverage with influenza vaccine. 

Based on data from the 2017 National Health Interview Survey (NHIS), influenza vaccine 

coverage was lower among Hispanic and Black adults compared to White adults in all age 

groups and among groups with and without underlying high risk conditions.

In planning for the upcoming 2020-2021 influenza season, CDC is pleased that manufacturers 

of US-licensed influenza vaccines are planning a record high amount of vaccine with more than 

180 million doses expected. Effective outreach will be needed to persons at higher risk, 

planning for potential need for social distancing in vaccine delivery, and in planning to extend 

the influenza vaccination season until December or later for distribution of all doses that are 

expected. Ongoing COVID-19 prevention activities provide opportunities to share influenza 

prevention messages and it will be important to focus on messaging for African American and

Hispanic communities, given the disparities in influenza vaccine coverage and COVID-19 

morbidities that have been observed.

CDC is also pleased to have been able to provide supplemental resources for public sector 

influenza vaccination for the 2020-2021 season. This includes supplemental funding to support 

immunization program activities and purchase of additional vaccines for use in adults. In most 

years, CDC has purchased about 500,000 doses for adults through federal contracts. This year, 

the agency has been able to purchase an additional 7.1 million doses. Some of these doses will 

be available late in the season, so it will be especially important that the vaccination season be 

extended into December or later. Community Health Centers (CHCs) provide an important 

partnership opportunity for state immunization programs to reach adults who otherwise might 

not be vaccinated. CDC appreciates the support of the National Association of Community 

Health Centers (NACHC) in facilitating these connections with its state programs.

In conclusion, there have been substantial disruptions to routine childhood vaccination services 

during the COVID-19 pandemic, though signs of recovery are now being seen. Catch-up for 

childhood vaccination needs to be undertaken now so clinical capacity can be directed to backto-school and influenza vaccination efforts in the summer and fall. Solutions are needed to 

existing disparities in influenza vaccination coverage in order to avoid these disparities if 

possible when there is a COVID-19 vaccine. CDC appreciates the support of immunization 

programs, partners, and healthcare providers in getting childhood vaccination back on track by 

supporting catch-up vaccination efforts and communicating with parents about safe well-child 

visits and vaccination during the COVID-19 pandemic.
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

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Open Discussion

Dr. Bell acknowledged the amount of effort and research focused on understanding the reasons 

for the ethnic and racial disparities in influenza vaccination coverage among adults. Recognizing 

that this is clearly multifactorial, she wondered whether Dr. Wharton could reflect on what the 

major drivers of this disparity appear to be.

Dr. Wharton emphasized that it is a complicated and multifactorial issue no doubt, and that she 

was not sure she had a very satisfying answer to Dr. Bell’s question. It clearly goes well beyond 

access. There is strong evidence of differences in vaccine perception, acceptance of 

vaccination by race/ethnicity, perceptions of the need for vaccination, and trust in 

recommendations from healthcare providers. All of those likely contribute. One of the aspects in 

which CDC is very interested is that it is known that quality improvement efforts (e.g., standing 

orders, prompts, strong provider recommendation) work to improve vaccine coverage among 

both children and adults. Whether those will be sufficient to reduce disparities is the question. 

The agency is pleased to be doing some ongoing work in association with the NACHC to try to 

better understand the degree to which disparities can be addressed through quality 

improvement and whether additional strategies will be needed. That is a focus of a great deal of 

work at CDC currently.

Dr. Poehling noted that the data shown on vaccine disparities was focused on adults and 

requested that Dr. Wharton speak about the vaccine disparities seen in children as well.

Dr. Wharton indicated that fortunately, the disparities seen in children are much lower. They are 

not non-existent, but they are much smaller in magnitude than seen with adults. The VFC 

program and the commitment of public sector immunization programs and participating 

providers ensures that vaccines are available to everybody.

Dr. Rockwell (AAFP) asked whether the messaging for African American and Hispanic 

communities is something CDC will be working on and putting out a statement in alignment with 

other national organizations that might confer more trust with those communities, or if this is 

something individual physicians should focus on in speaking with their patients. Regarding the 

epidemiology for SARS-CoV-2, she noticed that higher BMI was associated with higher 

morbidity. With the pregnant women’s study, it was specifically stated that a BMI over 30 was 

associated. She wondered whether a BMI number could be cited for children and non-pregnant 

adults.

Dr. Wharton indicated that there is some research underway to help inform communication 

efforts. There are external partnerships with other organizations that also are working on this. In 

addition, there will be other activities during the summer that are anticipated to help inform 

future activities.

Dr. Oliver indicated that underlying conditions, including obesity, were in the COVID-NET 

population with a BMI of over 35. The BMI over 30 study was conducted in NYC, not through 

CDC. CDC is collecting BMI data in children and adults.
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

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Dr. Goldman (ACP) suggested an advertisement campaign and education materials for adult 

medicine similar to that developed for children. Adult medicine is facing the same issues of 

patients not wanting to present to the office due to not feeling it is safe, along with a decrease in 

adult vaccination rates because people are staying at home.

Regarding disparities observed during the COVID-19 pandemic, Dr. Whitley-Williams (NMA) 

stressed that it is not just comorbidities and social determinants of health (SDOH). During the 

pandemic, barber shops, beauty salons, and churches have been closed. Sometimes those 

places serve as a source of information and communication to the community, as well as what 

is posted on social media. She applauded CDC’s efforts in terms of examining the various 

strategies to get the word out. She is very concerned about the distribution of vaccines when a 

COVID-19 vaccine does become available in terms of whether the structure will be in place to 

reach those who may be at greatest risk and who also may be more difficult.

Dr. Wharton emphasized that CDC shares those concerns and is trying to plan accordingly.

Introduction

Beth Bell, MD, MPH

Chair, ACIP COVID-19 Vaccines Work Group

Clinical Professor, Department of Global Health

School of Public Health, University of Washington 

Dr. Bell explained that there are a number of considerations about COVID-19 vaccination in the 

US that formed the foundation for the ACIP COVID-19 Vaccine WG’s work. First, there was 

recognition of the need for equitable access to safe and effective vaccines and evidence-based 

vaccination policy. As part of that, preparing for implementation of safe and effective COVID-19 

is a critical next step to protect the public and reduce the impact of COVID-19 on society. The 

increased risk of severe COVID-19 in vulnerable populations and racial/ethnic minority groups 

highlight the need for diverse representation in clinical trials and for ensuring equitable access 

to vaccines, regardless of the specific vaccination strategy or identified priority groups. The 

ACIP COVID-19 Vaccines WG was established to help inform evidence-based approaches to 

COVID-19 vaccination policy. 

The WG was established in April 2020 and has met weekly or bi-weekly since then. The WG’s 

role is the collection, analysis, and preparation of information related to COVID-19 vaccines for 

presentation, discussion, deliberation, and vote by the ACIP using an open and transparent 

process. The WG is comprised of 41 members, including ACIP voting members, liaisons, exofficios, and expert consultants. Areas of expertise of COVID-19 WG members include:

COVID-19 Vaccines
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

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Communications Immunology

Emergency Preparedness Infectious Diseases

Epidemiology Obstetrics

Ethics Pediatrics

General Medicine Public Health/Surveillance

Geriatrics Vaccine Administration/Delivery

Health Equity Vaccine Safety

Immunocompromised Hosts Vaccinology

Among the 41 WG members are 4 ACIP voting members, with Dr. Bell serving as Chair; Drs. 

Dooling and Mbaeyi serving as CDC Co-Leads; CDC experts; and the following consultants, 

liaison representatives, and ex-officio government members:

Consultants in Several Areas

 Vaccinology

 Microbiology/Immunology

 Safety

 Ethics

 Health Equity

Liaison Representatives

 American Academy of Family Physicians (AAFP)

 American Academy of Pediatrics (AAP)

 American College of Obstetricians and Gynecologists (ACOG)

 American College of Physicians (ACP)

 American Geriatrics Society (AGS)

 Association of Immunization Managers (AIM)

 American Medical Association (AMA)

 American Nurses Association (ANA)

 American Pharmacists Association (APhA)

 Association of State and Territorial Health Officers (ASTHO)

 Council of State and Territorial Epidemiologists (CSTE)

 Infectious Disease Society of America (IDSA)

 National Association of County and City Health Officials (NACCHO)

 National Advisory Committee on Immunization Canada (NACI)

 National Foundation for Infectious Diseases (NFID)

 National Medical Association (NMA)

 Society for Healthcare Epidemiology of America (SHEA)

Ex-Officio Government Members

 Biomedical Advanced Research and Development Authority (BARDA)

 Centers for Medicare and Medicaid Services (CMS)

 Department of Defense (DoD)

 Food and Drug Administration (FDA)

 Indian Health Services (IHS)

 National Institutes of Health (NIH)
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

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One of the first tasks undertaken by the WG was to develop terms of reference. The policy topic 

under consideration by the WG is use of COVID-19 vaccines in the US population. The WG 

activities are to: 1) review the safety and immunogenicity data for COVID-19 vaccines; 2) review 

the epidemiology of COVID-19 disease and identify potential target populations for vaccination; 

3) discuss potential vaccine prioritization plans in the event of early insufficient early COVID-19 

vaccine supply; 4) identify areas where additional data are needed to inform COVID-19 vaccine 

recommendations; and 5) develop COVID-19 vaccine policy options that ACIP may consider for 

recommendation. When considering the terms of reference, the decision was made to establish 

a Vaccine Safety Technical Subgroup in recognition of the importance of vaccine safety and the 

highly technical nature of the data that would be incoming. The role of the Vaccine Safety 

Technical Subgroup is to advise the main WG on the safety of COVID-19 vaccines, both during 

clinical development and post-licensure. 

The WG has been dealing with a number of factors related to decision-making in the context of 

many unknowns and uncertainties. The WG must stand for the principles of evidence-based 

decision-making, equity, and transparency in the process and recognizes the tension between 

the need to provide guidance and the limited available science base. The WG strives to develop 

a robust understanding of what is known, making sure that diverse voices are heard in this 

process. The WG makes decisions based on the knowns at the time, recognizing from the start 

that revisions will be needed as more information becomes available. This means that the WG 

must advocate for implementation of the essential strategies and systems to ensure that

pivotal data for decision-making are collected. The WG strives to continue to promote a 

feedback loop to evaluate the impact of recommendations and commit to revising accordingly. 

Dr. Bell indicated that the agenda for this session would include presentations on the following 

topics:

 COVID-19 Vaccine Development

 Landscape of COVID-19 Vaccines in Development

 COVID-19 Vaccine Prioritization Considerations

 WG Considerations and Next Steps

COVID-19 Vaccine Development

Dr. Matthew Hepburn

Lead, Operation Warp Speed Vaccines

Department of Defense/Department of Health and Human Services

Dr. Hepburn said it certainly was a privilege to share a few minutes of time with the ACIP and 

noted that he would like to make 3 general points. He indicated that he did not have any slides 

available for this presentation, part of which was because Operation Warp Speed (OWS) is still 

a work in progress and is still figuring out how they work together. As the work of the 

government can certainly attest, OWS is still figuring out its own clearance process for 

messages and materials that can be available publicly. OWS as group or entity may have been 

coming together over the past month or so, but it feels like they are a brand-new organization. 

As such, he requested ACIP’s latitude in terms of his lack of ability to provide a lot of specifics 

about what OWS is doing. OWS also wants to engage, talk, and discuss what they are doing 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

60

with ACIP as an entity and also with the experts who were part of the call and dialogue during 

this meeting.

With the understanding that OWS is a work in progress, Dr. Hepburn said he wanted to explain 

a couple of things. The first would be to talk through the OWS organizational structure and how 

they came about, and second to talk about some of the conceptual themes or compare and 

contrast of what OWS is and what it is not. OWS is a newly formed entity about which there has 

been a lot written in the public media and press which he thinks, unfortunately are 

misconceptions and they will have the chance to get that message out publicly to discuss some 

of those misconceptions and notions in the coming days and weeks. For the purpose of this 

meeting, he thought it was helpful to note that he sees OWS as an integration of some of the 

best efforts in the US government and resources available to accelerate a few products in order 

to have a safe and effective vaccine to respond to the pandemic.

Dr. Hepburn indicated that he is an infectious disease physician who served 23 years as an 

Active Duty Army Officer, retired, ran some vaccine antibody development programs in the DoD, 

and then was asked to be part of OWS as a DoD and HHS integrated effort. One of the key take 

home points is that OWS is not a secret organization that is working with unknown people and 

no one really understands what they are doing. He really does think it is just the opposite. They 

are taking advantage of the best in terms of expertise and capability within both HHS and DoD. 

It is nice because they actually are integrated, and he thought most of them could appreciate 

that. One of the things the federal government often struggles with is the ability to integrate 

across the different departments and agencies. He thinks OWS is a case in point on how they 

can and should integrate, and he is happy to be more specific on that.

As part of the Vaccine Team, each of the vaccines they plan to engage with has a Product 

Team that is composed of about 10 to 12 individuals. Those individuals are drawn from 

throughout HHS and DoD, including NIH, CDC, and a significant component from their 

colleagues at HHS BARDA, especially regarding contracting and program management. They 

also have Functional Leads. The first Functional Lead that cuts across all of their products is in 

the pre-clinical and clinical space. This is Chaired by John Mascola at the Vaccine Research 

Center (VRC) and is population with what Dr. Hepburn thinks are some of the best scientists in 

the government from the NIH, DoD, and elsewhere. The second cross-functional area is in 

manufacturing taking advantage of the best in government, but mostly from HHS BARDA. The 

third is led by Dr. Messonnier who leads a remarkable team in the distribution and 

administration category. This was put together in the previous 2 to 3 weeks, and Dr. Hepburn 

likes how they are working very well together. He expressed his hope that everyone could 

appreciate the advantage of taking a lot of different components in the government and putting 

them together for this common focus.

Dr. Hepburn said they could argue about the name OWS and how it may lend itself to 

misconceptions, but he did not think that was the point of this conversation. Why he is very 

excited about this is that it does entail putting in significant resources for multiple vaccines to be 

developed, and to be developed on an accelerated schedule. One of the key points they make 

when they talk about acceleration is that this is not acceleration in terms of cutting corners and 

this is not acceleration in terms of compromising safety standards. Rather, they are looking at 

accelerating where they might otherwise do thinks in parallel because of resources and financial 
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risk. For example, one of OWS’s main goals is to make sure that they can manufacture at scale. 

He thinks everyone appreciates that one of the key components of manufacturing and scale is 

starting early. In a typical vaccine product development pipeline, some of the large-scale runs 

might be done after there are more proof of concept data. In this case, they said they are going 

to take more financial risk and start larger scale manufacturing operations earlier. He thinks it is 

a really good example of that approach. There may be a few vaccines for which they make a lot 

of doses and those vaccines may not pan out in clinical trials. That is lost financial resources, 

but really does not compromise the safety and effectiveness of the vaccine. OWS is following 

product development expectations that would be expected. 

While Dr. Hepburn said that he was not going to go into which products they are/are not 

funding, OWS has broadly looked at funding sources and resources across the US government. 

They have not said to cut things to be part of this program or said that those who do not get 

picked will be cut and do not get any US government funding anymore. Rather, OWS is going 

through a continuous assessment process of which vaccines they think are most promising to 

deliver significant doses by the end of the calendar year 2020 or within the first quarter to half of 

2021, and looking at different ways they can accelerate those. One of the big things that is 

coming up soon, that OWS’s NIH colleagues in particular have been working on quite a bit, is 

thinking through the large-scale clinical trials that would be associated with this. These are 

going to be individualized and case-by-case, but one of the things most of the members have 

seen is a Science article by Lawrence Corey, John Mascola, Anthony Fauci, Francis S. Collins 

recently that advocated for harmonization wherever possible, especially for the large-scale 

Phase 3 clinical efficacy trials. That is OWS’s intention and Dr. Hepburn thinks their colleagues 

at the NIH are well-positioned to take an active role in that. Further, OWS is aiming to partner 

with the NIH Clinical Trials Network (CTN) where it makes sense and not necessarily 

exclusively, to be partners in some of the large Phase 3 clinical trials that they anticipate will be 

coming up in the coming months.

Finally, Dr. Hepburn said that where OWS’s CDC colleagues have been absolutely critical in 

playing a leadership role, fingers crossed, is if there is a scenario in which there is a safe and 

effective vaccine and that vaccine is ready for distribution, is with working through all of the 

complexities and challenges with distributing that vaccine. He thought a very fair question from 

the ACIP would be, “How far along are we in that process?” He could defer to Dr. Messonnier 

and CDC to comment further, but he thought from an OWS standpoint, in their first few weeks 

they focused on the earlier product development and making some of those important decisions 

to accelerate the product development pipeline. OWS does have an eye toward how these 

vaccines would be distributed based on their indications, which populations would benefit most 

from vaccination, where side effects would be anticipated—all of those complex issues. Those 

are critical issues that need to be addressed, which he acknowledged that most of those on the 

phone are expert in. OWS’s intention is to address those in the coming weeks. As they address 

those challenges, as was outlined in the previous conversation and that he thought would be 

discussed throughout the day, OWS needs ACIP’s help and hopefully has made clear that they 

are leveraging a lot of expertise in the US government. More formally from an OWS standpoint, 

they sincerely welcome the dialogue, input, and future conversations with ACIP. In closing, Dr. 

Hepburn said that he would be happy to field questions and would stay on the line for as much 

of the meeting as possible.
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Discussion Points

Dr. Romero said that ACIP looks forward to working with OWS as COVID-19 vaccine 

development moves ahead. He asked how OWS sees the role of the ACIP in determining risk 

populations and making recommendations for distribution of available vaccines in the future. He 

pointed out that the ACIP has a nearly 60-year experience in making recommendations 

regarding the use of vaccines for the control and prevention of disease in the US.

Dr. Hepburn said that simply put, OWS sees the ACIP’s role as essential in helping to think 

through the challenges and essential for ACIP’s input, advise, and expertise. For him 

personally, he is happy to engage with ACIP as frequently as needed. Because of ACIP’s close 

relationship with the expertise at the CDC, he is also making the assumption that he thinks is 

very valid, that that dialogue occurs and the ACIP is informing the OWS team through the 

dialogue that they have with the CDC on a routine and informal basis. OWS is happy to include 

ACIP where it is appropriate and ask for ACIP’s advice. In terms of right now, as ACIP could 

appreciate, OWS is still in the early stages for these vaccines. If they are successful with 

resources to accelerate the timelines on these, in the coming weeks and months, they will 

welcome the dialogue once they have a little more understanding of how these products work 

and a little more understanding of which products they think may be able to achieve Emergency 

Use Authorization (EUA).

Dr. Cohn thanked Dr. Hepburn and clarified one point that he made, which is that all discussions 

between ACIP and CDC occur in a public, open setting. She wanted to ensure that the audience 

understood that.

Dr. Hepburn thanked Dr. Cohn for that clarification and said that he thought this was a great 

forum to dialogue. OWS is happy to share information, let ACIP know what they are doing, and 

also be inspired by ACIP’s input, suggestions, and guidance.

Dr. Frey emphasized that a lot of the timelines are being compressed with the Phase 3 studies. 

She inquired as to who/how a final decision will be made, at what point OWS will decide to say 

that a vaccine is efficacious and launch it, and how they will work with FDA and others to make 

these decisions.

Dr. Hepburn said that in terms of the product development that would be expected for this, they 

are going to follow the process that vaccine product development usually follows in terms of the 

clinical trials process under good manufacturing—all of those things that would normally be 

expected for any vaccine development. OWS is going to do all of that. That is the expectation 

and that will include frequent dialogue with the FDA at every step where it is appropriate and 

ultimately, if there is a situation where the safety and efficacy are good enough, to apply for 

EUA. OWS’s role is to fund the companies. The vaccine development companies under contract

will receive resources to do a lot of these functions. When the DoD funds a vaccine project, they 

fund the company to do this. With HHS BARDA, it is the same thing. OWS is funding the 

companies to do that and they are responsible for many of these steps in product development. 

What he is excited about is that by leveraging the expertise in the government as they think 

about clinical trials, clinical trials design, and running these clinical trials at sites, OWS can 

leverage all of that expertise from the NIH, CDC, and BARDA to ensure that a clinical trial is run
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not just by a vaccine company, but a very high quality clinical trial that has harmonization, 

meaning that there are common endpoints that may offer an opportunity to look at different 

vaccines to have some comparability. It also will allow them to leverage trying to answer these

critical scientific questions such as correlates of protection. Again, it is resources through 

contracts to drive a vaccine process that will follow the typical steps. But in that program 

management and leveraging OWS’s US government team, Dr. Hepburn thinks that they can not 

only accelerate products, but they can actually learn a lot too about those products. 

Dr. Fink (FDA) reiterated that in the clinical development of all of the COVID-19 vaccine 

candidates, the FDA will continue to perform independent review and oversight of the 

development process and will make the final determination based on the data available as to 

the safety and appropriateness of any progression in clinical development and providing the 

vaccine, even in the context of clinical study, whether that is first a human study or advancing to 

Phase 3 efficacy studies, and wider availability of vaccine candidates through licensure.

Dr. Talbot said that as an adult immunologist and vaccinologist, this is incredibly exciting and 

she is looking forward to all of the collaboration that is ongoing. She is also very excited 

because this gives them some time to prepare as they wait for data. As someone who conducts 

viral respiratory disease surveillance and vaccine effectiveness is that there is not a very good 

way of tracking adult immunizations in the US. The state registries vary greatly. One thing that 

can be done in preparation for a new vaccine or vaccines is to strengthen and enhance state 

registries so that adult data can flow into them, and then as time goes on, real-time vaccine 

effectiveness and safety data can be provided much more quickly and thoroughly than is 

possible at this time.

Dr. Hepburn agreed and thought they could recognize the benefit of the OWS integrated 

approach having the CDC on their team and part of this entire process. He has heard this from 

them and he deferred to their expertise in terms of the how, but he could not agree more that 

this is an opportunity to do this right—not minimizing the challenges. He recognized that there 

are enormous challenging in developing a vaccine against this virus. But, if they are successful, 

now is the time to think through those latter phases in terms of distribution and tracking as Dr. 

Talbot correctly pointed out.

Ms. Finley (AIM) said that one thing which caught her attention was integration of the best 

efforts in government. She encouraged OWS to build on the existing plans and infrastructure. In 

working with CDC, they are probably aware that there are 67 immunization awardees that 

address enrolling providers, distributing vaccine directly to them, overseeing storage and 

handling, working for the Immunization Information Systems (IIS). Many of them worked closely 

with CDC through the 2009 pandemic, so she encouraged building upon the effective systems 

that were developed.

Dr. Hepburn said he agreed 100%, noting that everyone could appreciate that what is going to 

happen in the fall is inherently unpredictable in and of itself and in terms of the effectiveness of 

a vaccine or multiple vaccines. It would be great if there are choices and options. Regarding 

how effective they will be and how effective they will be in what populations and scenarios 

raises a lot of complexity right now. The only thing that is certain is uncertainty, meaning that 

they are going to have to plan ahead but also be very flexible. They need to utilize the expertise 
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and mechanisms for vaccine distribution that are currently in place, but also pivot and be flexible 

to respond to the unique scenarios in which they might find themselves. Vaccine tracking would 

be a good example, but he thinks there are many others. OWS will rely on ACIP’s expertise to 

inform them of the best way to get this done.

Dr. Lee expressed her hope that there continues to be a real-time connection between OWS 

and ACIP, especially as they continue to review evidence in real-time as a picture emerges. 

This particular process offers the opportunity to have openness and transparency about the 

process of ACIP’s decision-making. There is a critical nature of a COVID-19 vaccine in general 

to the health and welfare of the general population, but also she sees this vaccine as being 

critical to ensuring that public trust and engagement can be maintained in immunizations in 

general. She expressed her hope that this might be an opportunity for early engagement and 

partnership. In the pre-distribution phase, knowing that certain vaccines may be targeted for 

certain populations because of their benefit/risk profile, it would be extremely helpful to think 

about targeted educational and engagement efforts with those priority populations in the predistribution phase. Even more critical and incredibly important is to ensure that in the postdistribution phase, tracking can be done. Vaccine safety surveillance in the post-distribution 

phase will be critical to continuing to inform decisions in real-time. She anticipates that they will 

have to adapt as they go, because there are so many uncertainties, but being able to link more 

tightly between distribution, tracking, monitoring, and particularly who is getting the vaccine in 

terms of risk populations, occupational risk exposure, age, et cetera will be incredibly important 

for ACIP as they are monitoring vaccine safety after distribution occurs.

Dr. Hepburn agreed 100%. He feels like it is a privilege to be part of a US government team that 

includes the CDC that has a lot of experience and thoughtfulness in terms of how to accomplish 

that mission, leveraging experience from a lot of other issues and incredible challenges in 

communicating effectively about vaccines. He was glad that their FDA colleagues were able to 

chime in about some of the tenants they had talked about during this meeting, such as 

transparency and ensuring that the vaccine is safe and effective, to make it clear about their 

independence in the review process. OWS has to do a better job of communicating that as an 

institution, but he thinks they will. They certainly will value ACIP’s help in this. One thing he 

would ask ACIP, the people on the phone, and the government team is to learn the lessons of 

the past in terms of how they communicate about vaccines and also think about how to stay one 

step ahead of the misinformation. He said that since he is not an expert in communication, he 

will rely on others to be thoughtful about that. OWS anticipates that there will be a lot of 

misinformation and how deleterious that can be. He wants them to collectively be creative about 

how they stay one step ahead of it. He agreed that clear communication and transparency is a 

great first step. 

Dr. Bell took this opportunity to reiterate a few of the points made. She was very happy to see 

and hear that OWS and ACIP share many common principles of transparency, integration, and 

using science-based policy. She reiterated that the ACIP is comprised of experts who have 

been appointed by the HHS Secretary, and that the ACIP has been in existence for decades. As 

Dr. Hepburn mentioned, OWS is a new organization. ACIP stands ready to help OWS in its 

efforts. They need to work together to succeed. The ACIP has developed a very well-oiled and 

high respected process for taking scientific information as it becomes available and using it to 

develop policies that are evidence-based and look to have the largest impact in terms of 
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65

preventing morbidity and mortality and reducing spread, and which are designed to strengthen 

and continue to inspire confidence of the public in the way in which ACIP make decisions about 

vaccine policy in the US. As Chair of the COVID-19 Vaccine WG, she invited Dr. Hepburn to 

engage with them early and often. ACIP feels that they have quite an important role to play and

that they can help with many aspects of this process as it develops. 

Dr. Hepburn said that he greatly appreciated Dr. Bell’s comments and is certainly in favor of 

continuing the dialogue. 

Landscape of Candidate COVID-19 Vaccines

Kathleen Neuzil, MD, MPH, FIDSA

Director, Center for Vaccine Development and Global Health

University of Maryland School of Medicine

In terms of what is known about SARS-CoV-2 pathogen and immunity, Dr. Neuzil emphasized 

the importance of the spike glycoprotein. In terms of vaccine development lessons from other 

coronaviruses, looking at sequence comparison, the MERS Spike S protein is about 30% 

homologous to SARS-CoV-2. The SARS Spike S protein is 80% homologous. It is known that 

both of those prior coronaviruses had good vaccine responses to several vaccine constructs in 

animals. There were vaccines that made it to Phase 1 human for both SARS and MERS. They 

showed broadly neutralizing antibodies. MERS development continues. Unfortunately, SARS 

investments were re-allocated. Therefore, SARS vaccine development did not get very far.

The SARS-CoV-2 Spike protein is important for viral entry. Everything mentioned earlier from 

Dr. Thornburg about immunity is exactly what makes this spike protein a target for vaccine 

development. As Dr. Thornburg very nicely explained the characteristics of this protein, so Dr. 

Neuzil did not repeat them. She pointed out that in the context of vaccine development, they 

would hear a lot about the type of spike protein used in terms of whether it is the full length 

protein, receptor binding domain, and whether it is the prefusion or post-fusion form. Similarly, a 

lot of Dr. Thornburg’s explanation was about why certain antibody tests are also relevant to 

vaccine development. The spike protein is a metastable protein that undergoes a major 

structural rearrangement to fuse the viral membrane with the host cell membrane. The idea with 

vaccines is to try to disrupt that binding. Some people are using the wild-type confirmation, but 

there also has been a prefusion confirmation and stabilization of the prefusion form of the spike 

protein described by investigators at the VRC at NIH where they inserted two stabilizing proline 

mutations that have been effective for other betacoronaviruses. 

In terms of what is known about immunity in humans, attempts are made to try to parrot vaccine 

development on what works with natural infection. Unfortunately, little is known. There is an 

immune response post-infection. Neutralizing responses are seen post-infection. They do not 

cross-react with the SARS virus. What is not known that would be helpful to vaccine 

development is the level of antibody needed to prevent reinfection, the duration of protection 

from natural immunity, or how important T-cell immunity is to prevent infection or reinfection.
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There are some hints from animal models. In fact, there are two non-human primate (NHP) 

models that show that if rhesus macaques are infected and an attempt is made later to re-infect 

them, the initial infection does protect against re-challenge. This is a positive for developing a 

vaccine. However, it is known that these experiments are done with relatively small numbers of 

animals and the re-challenge was done fairly close in time to the initial challenge at 28 days in 

one study and 35 days in the other. Though this is still an unanswered question, animal models 

are supportive.

It is known that vaccine development is a lengthy, risky, and expensive process. Generally, an 

accelerated timeline might mean 6 to 7 years compared to the usual 15 to 20 years. It is 

important to understand that these timelines are being compressed with investments in finances 

and resources with at-risk manufacturing and other at-risk choices. Compromises are not being 

made in terms of safety or safety follow-up. Nevertheless, one target being estimated for COVID 

vaccines is 12 to 18 months. This would represent a quite rapid timeline for initial identification 

of the organism almost to vaccine development.

In terms of vaccine platforms and attributes, all of the platforms that are licensed for another 

vaccine target are also slower to initially mix. When people ask Dr. Neuzil why it is the unproven 

technologies the government is currently testing, it is because they have the advantage of 

speed of manufacture. The tried and true licensed platforms will be coming along in the next 

month and also will be tested. That being said, the reason that these new platforms have not 

been licensed does not necessarily mean that they do not work. While this is a scientific 

endeavor, vaccine development is also business- and market-driven. Many of the DNA and 

RNA vaccines have been used for emerging infections in which the market then went away, 

such as SARS in which the vaccines were stopped, and the investments were reallocated to 

something else. Or perhaps they were used for a vaccine such as influenza for which there is a 

quite competitive market in which a new vaccine may not be able to compete. The fact that 

there is not yet a licensed platform should not imply that these are inferior vaccines that could 

not be safe, immunogenic, and effective.

In terms of dosing, a single dose would be nice in an outbreak situation. It is highly unlikely in a 

naïve population for most of these platforms that there will be efficacy after a single dose. 

However, most of the platforms will require multiple doses. Scale is also important. This is a 

pandemic and there are 320 million people in the US and 8 billion people in the world. If each of 

them needs 2 vaccines, it is clear that having platforms that are able to be scaled will be 

necessary and it would be nice to have multiple wins with 3, 4, or 5 licensed vaccines on the 

market in a short timeframe.

Regarding the COVID-19 vaccine candidates that are in clinical development, one of the 

furthest along is the non-replicating viral vector that is in a Phase 1/2/3 study in the United 

Kingdom (UK). This is an adenovirus vaccine. There were similar but small numbers of people 

in these trials for MERS, influenza, tuberculosis (TB), chikungunya, and Zika vaccine. This 

vaccine will enter clinical trials in the US hopefully in the next month and a half or so. There also 

is a non-replicating viral vector based on an adenovirus Type 5 by a Chinese manufacturer that 

has entered Phase 2. The second clinical trial in the US was with an mRNA vaccine by 

Moderna. While there has never been a licensed platform with the mRNA vaccine, the same 

platform has been used for influenza, Zika, and chikungunya. Novavax has a protein subunit 
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vaccine that has started Phase 1 testing in Australia. Pfizer in collaboration with BioNTech has 3 

different formulations of an mRNA vaccine currently in Phase 1 in the US and Europe. There is 

a DNA vaccine by Inovio. Multiple Chinese developers have inactivated vaccines, plus or minus 

alum, in Phase 1/Phase 2 development. The ChAdOx1-S, mRNA, a protein subunit vaccine, 

and a DNA vaccine should be expected soon in the US.

One reason the nucleic acid vaccines can make it to clinic a lot faster is that what is needed is 

the genetic sequence. Then the genetic sequence can just be substituted for whatever genetic 

sequence was in the prior formulation of the vaccine. That is, a COVID RNA replaces an 

influenza RNA. No fermentation or optimizing cell cultures are required, so these can move very 

quickly. A DNA vaccine has to make it to the nucleus of the cell and needs some help with that, 

which is why either electroporation or devices are used to deliver DNA vaccines. Similarly, RNA 

vaccines only need to make it into the cytoplasm. They are encased in a lipid coat that helps 

them to enter cells. An individual’s myocytes make the viral proteins and then the body makes 

the immune response.

In terms of the Moderna vaccine, a peer-reviewed publication is expected soon with the Phase 

1 results. Phase 1 began in healthy adults 18-55 years of age in March 2020. As announced on 

May 18th, after 2 doses all participants evaluated at the 25 μg and 100 μg dose seroconverted 

with binding antibody. Because there is not a level of binding antibody known to be protective, 

they are being compared to convalescent sera. The convalescent sera can be quite diverse in 

the responses. Nonetheless, these participants had binding antibody levels at or above the 

levels seen in convalescent sera. Similarly, neutralizing antibody titers (the ability to stop the 

growth and spread of the virus) reached or exceeded neutralizing antibody titers seen in 

convalescent sera for patients who had recovered from COVID. These vaccines were generally 

safe and well-tolerated and provided full protection against viral replication in a mouse challenge 

model. It is anticipated that Phase 3 will begin in July 2020.

The viral vector vaccines are another example of gene-based vaccines for which a protein does 

not need to be made, so these can be manufactured faster and get into clinics sooner. This may 

be a replicating viral vector such as a weakened measles vaccine for which the coronavirus 

spike gene is inserted or a non-replicating viral vector vaccine such as the adenovirus vaccine. 

The myocytes make the proteins and the body hopefully will make an immune response. A 

publication by Feng-Cai Zhu et al in May 2020 discussed the safety, tolerability, and 

immunogenicity of a recombinant adenovirus type-5 vectored vaccine. Regarding adverse 

events at a low, medium, and high dose, there was reactogenicity of pain at the injection site in 

about 50% or more participants at all 3 dose levels. For adults, Grade 3 fever was lower. Any 

fever was about 40% to 50%, so there is some reactogenicity with these vaccines. 

Immunogenicity was seen with the enzyme-Linked Immunosorbent Assay ELISA antibody and 

the neutralizing antibodies in the lower, middle, and high dose. The antibody peaks at Day 28. 

There is a dose-dependent response for both the ELISA and neutralizing antibody. As has been 

seen with other adenovirus vaccines, a high pre-existing Ad5 neutralizing antibody response

compromised the neutralizing antibody to COVID post-vaccination, regardless of vaccine dose. 
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All of these trials go through full FDA review and full ethics review and safety is taken very 

seriously every step of the way. In addition to the reactogenicity measures, animal studies are 

being done in multiple animal modes to look for any vaccine-enhanced illness. The question 

was asked earlier about antibody-dependent enhancement of viral replication. This has been 

shown primarily by viruses with an innate macrophage tropism such as Dengue. In the case of 

COVID, there may be more concern with a vaccine-enhanced respiratory illness. So what is 

being looked for in the animal studies are the inflammatory cytokines, a Th1 versus Th2 

response, and looking at neutralizing antibodies versus non-neutralizing antibodies. In terms of 

what this means for human studies for a vaccine-enhanced respiratory illness, one might worry 

about that occurring a little bit later in time at perhaps 1 to 2 years after getting a vaccine when 

the functional neutralizing antibodies start to wane. In all of the Phase 3 trials with the 

government, participants are being followed out to 2 years. 

In summary, safe and effective vaccines are needed that are accessible, affordable, and

globally available for COVID-19. There is a robust pipeline of promising candidates in clinical 

development, and multiple wins are needed. There are many challenges. This is a new disease

with poorly understood immunity. As these large Phase 3 trials are planned, there is an 

uncertain trajectory of the outbreak and whether there will be sufficient attack rates to show 

efficacy. Vaccine safety will be meticulously assessed. If enhanced disease occurs, it will be 

carefully assessed, and immune mechanisms will be investigated. 

Discussion Points

Dr. Atmar observed that while some of the safety concerns suggested may not show up for 1 to 

2 years after vaccination after neutralizing antibody wanes, an efficacy signal may be evident 

earlier, at least for short-term protection. In consideration of rolling out vaccines as expeditiously 

as possible, he wondered how to balance early signals of potential efficacy against unknown 

risks of safety that may not appear until later during the follow-up.

Dr. Neuzil replied that depending on the vaccine construct, she did not know that they would 

expect antibody-dependent enhancement for this particular disease based on what is known 

about the immunology. Likewise, enhanced respiratory disease has been seen primarily in 

children. That may be partially due to the anatomy and the small airways. Nonetheless, because 

with the original SARS and MERS there was a lot of discrepancy in terms of some animal 

models showing disease enhancement and some not, this will be very carefully explored in 

animal models. In the interest of time, she did not show the animal models that have been 

conducted, but there are quite extensive studies being done in animals to look for any signals. 

There is a risk-benefit ratio in terms of development, evaluation, and use of vaccines. In the 

midst of this pandemic, there is unprecedented morbidity and mortality in high-risk groups and 

unprecedented economic consequences. The benefit side of these vaccines must be 

considered. It would be fantastic if a vaccine is licensed sooner and has to be given to the 

control group, the original participants would continue to be followed. She welcomed comments 

from the FDA as well.
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

Dr. Fink (FDA) added that FDA is looking at many potential sources of data to inform the risk of 

enhanced respiratory disease throughout the clinical develop of COVID-19 vaccine candidates. 

These sources of data include characterization of immune response in the animal models and 

early phase clinical study participants, neutralizing and antibody responses, Th1 versus Th2 

polarization, the ability of the vaccine to protect animals against challenge in appropriate animal 

models, and looking for histopathological evidence of enhanced respiratory disease to the 

extent that those types of studies are feasible. As Dr. Neuzil mentioned, there will be careful 

follow-up of study subjects for the long-term of 1 to 2 years at least to continue to assess 

vaccine safety for participants in early studies and Phase 3 efficacy trials, even if there is a 

signal for efficacy or at least demonstration of efficacy sufficient to support wider distribution of 

the vaccine before longer-term follow-up has been completed for all of the subjects.

Dr. Baker (IDSA) asked whether there would be a single-dose arm evaluation in the US trials or 

if all arms would be 2 doses to begin with.

69

Dr. Neuzil replied that this depends upon the vaccine. The furthest along are the RNA vaccines. 

Everything that is known about mRNA vaccines is that it is likely to take more than one dose, so 

those will be 2-dose vaccines. The adenovirus vaccine that is being tested in the UK is being 

tested as a single dose vaccine. Some subjects are receiving 2 doses, but the majority are 

receiving 1 dose. It is possible that some of the viral vector vaccines will be single dose or there 

will be both a 1- and 2-dose arm as part of the trial.

Dr. Poehling observed that there is a tension when thinking ahead about the compressed 

timeline and RCTs. One is to make sure what is going to happen in healthy persons, but it is 

known in COVID-19 that people with obesity and other underlying conditions have more 

disease. Consideration must be given to balancing the need to represent them and other age 

groups.

Dr. Neuzil indicated that the Phase 1 trials and the data she was able to show so far were in 

young and middle-aged healthy adults. In fact, all of the Phase 1 trials quickly expanded to older 

adults 65 to 85 years of age or even older. People are aware of the epidemiology and where it is 

important to be sure to understand where these vaccines work. Most of the clinical trials with 

which she has been involved are including older age groups, people with chronic diseases, and 

are targeting a relatively modest to high percentage of people by setting benchmarks for getting 

at least X percent of people in some of the high-risk categories.

Dr. Szilagyi inquired as to when Dr. Neuzil thinks there will be trials with children and whether 

she had any sense about the different platforms that might suggest whether the efficacy would 

vary across the platforms for children, older adults, and/or race and ethnicity.

Dr. Neuzil indicated that there will be trials in children, though she could not indicate timing, 

plans, or how quickly. One of the first vaccines and the further ahead, the ChAdOx1-S at 

Oxford, already has plans to age deescalate relatively soon. While she did not have the exact 

timeline, it is part of the clinical development plan. In the US, there is a team thinking carefully 

through this, how it should be done, and preparing for these trials when they feel it is safe to do 

so. In terms of a construct, just getting back some of the Phase 1 data, which they do not have 

yet, in the different age groups will be very helpful to look at the difference. It is known that for 

many vaccines, immunogenicity starts declining as early as in the 40s. This is seen with
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influenza vaccine as early as in the 50s. It is known that immunesenescence is real. Looking at 

some successes in the older populations, higher doses of antigen are used for influenza vaccine 

and adjuvants with protein subunits that have been successful for zoster and influenza. There 

are vaccines that can work better in children. What is not known is whether that is because they 

are naïve or because they are children. It is a great question and it may well be that if there are 

multiple constructs, there will be formulations that are better for different age or risk groups. 

They also should not forget that monoclonal antibodies are being tested in terms of whether that 

could be used for post-exposure prophylaxis (PEP) in, for example, very debilitated elderly or 

immunocompromised individuals who may not be able to mount an immune response to any of 

these vaccines.

Dr. Bernstein wondered about how adequate sample sizes are being established as they move 

through the phases of vaccine development and they want to use them in multiple populations, 

especially those at high risk, for each of the platforms and for multiple populations.

Dr. Neuzil indicated that the initial trials will probably be close to 30,000. Part of the reason for 

that is that the attack rate is unpredictable, and speed and timing are important. They can either 

increase power by increasing sample size or the trial can go longer. In a pandemic, it is 

preferable not to have the trail go longer. She believes that these will be well-powered efficacy 

studies.

Dr. Frey observed that mouse and NHP models are frequently used to study responses to 

experimental COVID vaccines, but she wondered what the best animal model is for studying 

SAEs, specifically enhanced disease, to these vaccines or whether they really know.

Dr. Neuzil said she was not sure what she would use as a gold standard for that. If the gold 

standard is human disease, that is not yet understood.

Dr. Fink (FDA) added that the NHP model is probably the best at this time based on prior 

experiences with other coronavirus vaccines. His understanding is that there has been work 

more recently on other models such as hamster models. There is ongoing work to identify, 

develop, and characterize animal models that potentially could serve to evaluate the potential 

for enhanced respiratory disease.

Dr. Cohen indicted that they could try to include a brief update on animal models and studies 

during the next virtual ACIP meeting.

Ms. Bahta asked what is being done to ensure that the cohorts being studied are representative 

of the US population, particularly among communities of color where a higher proportion and 

more severe disease are occurring.

Dr. Neuzil acknowledged the recognition that Native Americans, African Americans, and 

Hispanic populations are suffering disproportionate morbidity and mortality. The rapid timeline is 

working against investigators because it is known that trust is built over time, which there is not 

a lot of. They are trying to capitalize on already established mechanisms to reach these 

communities. CDC is involved in some of these committees in terms of outreach and identifying 
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the leaders of some of these minority communities as quickly as possible so that they are wellrepresented in the research efforts. 

COVID-19 Vaccine Prioritization Considerations

Sarah Mbaeyi, MD, MPH

Co-Lead ACIP COVID-19 Vaccine Work Group

Medical Officer, National Center for Immunization and Respiratory Diseases

Centers for Disease Control and Prevention

Dr. Mbaeyi review the WG’s considerations for COVID-19 prioritization. Although the goal is to 

offer vaccine to the entire US population, identifying priority groups for COVID-19 vaccination is 

essential to support vaccine implementation planning. This planning needs to begin prior to 

vaccine approval so that vaccine can be distributed without delay once available. However, 

vaccine prioritization is challenging due to incomplete information on COVID-19 epidemiology 

and vaccines, including characteristics, timing of vaccine availability, and number of anticipated 

doses. Regardless, it is essential to start identifying priority groups now with the information 

available to date, with continuous reassessment as data become available. Identifying priority 

groups for COVID-19 vaccine will allow for strengthening vaccine distribution networks to reach

the target group, develop state and local micro plans for vaccine implementation, create 

communications strategies to promote vaccination in priority groups, and plan evaluations to 

rapidly monitor vaccine safety, effectiveness, and coverage. 

Although there are important differences between COVID-19 and influenza, reviewing the 

pandemic influenza experience and lessons learned is useful in planning for COVID-19 vaccine 

prioritization and implementation. Preparing for vaccination during a pandemic has long been a 

priority of CDC and the US government. Prior to the 2009 H1N1 pandemic, multiple efforts were 

undertaken to outline the initial vaccine prioritization strategy, gain public and stakeholder input 

on priority groups, and develop guidance for allocating and targeting influenza vaccine during a 

pandemic. Following the emergency of the pandemic H1N1 virus in April 2009, vaccine first 

became available in October 2009 during the second wave of disease. ACIP recommended 

priority groups for initial vaccination, including certain persons at increased risk for severe 

disease and HCP, followed by vaccination of the general population. Other essential workers 

were not among the initial priority groups as that pandemic was not deemed to threaten the 

critical infrastructure and societal function.

However, several challenges were encountered during the vaccination response. Public 

demand for vaccine was highest during the period when a large number of cases were still 

being reported and vaccine supply was low and targeted toward the priority groups. Once 

vaccine was widely available, the pandemic had started to wane in the US and public demand 

for vaccination was low. By late January 2009, vaccine coverage was 20% among the US 

population. The challenges of vaccine supply and demand were noted to have shaped other 

aspects of the response. Notably, the overly optimistic vaccine supply projections led to raised 

expectations that were identified initially, leading to logistical and communication challenges. In 

addition, restrictive enforcement of priority groups paradoxically led to a vaccine surplus in some 

places. Additional challenges were encountered when expanding vaccination beyond the priority 

groups, including when to do so and how to communicate it effectively to the general public. The 
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72

importance of population values and vaccine prioritization was also noted. For example, the 

exclusion of older adults in the initial priority groups led to overall reduced acceptance of 

vaccine in AI/AN populations because of the important role the elders play in those 

communities. Finally, while it is necessary to have national guidance, state and local flexibility in

vaccine implementation is important due to the varying needs in infrastructure despite 

challenges that may arise when challenges vary across jurisdictions. While these lessons 

learned from the H1N1 experience are valuable, the complexity of the COVID-19 pandemic

likely will lead to new challenges. 

Based in part on lessons learned from the H1N1, guidance for allocating and targeting 

pandemic influenza vaccines was revised in 2018. In this revised guidance, occupational and 

high-risk populations are grouped into tiers for vaccine prioritization. This guidance serves as a 

useful framework for adaptation to COVID-19 vaccine prioritization. As mentioned before, the 

prioritization framework is a roadmap for vaccine program planning. The tiered priority groups to 

be adapted for COVID-19 vaccination would need to be adapted based on the burden of 

disease and severity in risk groups, the pandemic’s impact on society and critical infrastructure, 

characteristics of the vaccines, and the number and timing of doses that will be available. 

Taking these factors into account, the WG discussed considerations for identifying COVID-19 

vaccine priority groups. ACIP provides advice to the CDC Director and HHS Secretary on use of 

vaccines in the US civilian population in a transparent, evidence-based process. To help inform 

ACIP deliberations around use of COVID-19 vaccines, including the identification of priority 

groups for vaccination, the work group reviewed the epidemiology of COVID-19; characteristics 

of vaccine candidates under development; and evidence-based vaccine recommendation, 

ethics, and equity frameworks. The WG first developed proposed objectives for the COVID-19

vaccine program, which are to: 1) ensure the safety and effectiveness of COVID-19 vaccines; 2) 

reduce overall transmission, morbidity, and mortality in the population; 3) help minimize the 

pandemic’s disruption to society and economy, including maintaining healthcare capacity; and 

4) ensure equity in vaccine allocation and distribution. The objectives formed the basis for 

developing considerations for priority groups for vaccination.

Because of the current gaps in the understanding of COVID-19 disease and vaccines, the WG 

made a number of guiding assumptions when considering priority groups for vaccination. In light 

of the evolving understanding of COVID-19 epidemiology and immunology, the WG assessment 

is that prioritization should occur based on the information available to date and be continually 

defined as new data become available. The WG also assumes that a substantial proportion of 

the US population, regardless of age, location, or occupation remains susceptible to COVID-19. 

Second, there are currently no data on the safety and efficacy of COVID-19 vaccines under 

human clinical development in the US that are publicly available. Vaccines will not be 

administered until safety and efficacy have been demonstrated. However, the WG feels that 

concerns for reduced efficacy in certain populations such as older adults and 

immunocompromised individuals should not preclude them as priority groups while data are 

pending. Finally, the timing and number of vaccine doses that will become available are still 

unknown. The WG assumes that the number of initial doses is still unknown. The WG assumes 

that the number of initial doses may not be sufficient to vaccinate everyone in the priority 

groups, necessitating sub-prioritization. In addition, the WG assumes that vaccine doses will 

become available in incremental quantities over several months.
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The WG then used principles for multiple frameworks to guide discussions on priority groups. 

The WG reviewed the pandemic influenza framework in which vaccines allocation decisions are 

made on the basis of burden of disease and severity, pandemic severity and impacts on society, 

and vaccine supply. Building off of this, the WG reviewed principles from the Evidence to

Recommendations (EtR) Framework that ACIP uses to make evidence-based vaccine 

recommendations, including the burden of disease and severity, benefits and possible harms, 

values of the target population, acceptability to stakeholders, and feasibility of implementation. 

Finally, the WG reviewed ethics and equity principles, including the desire to minimize death 

and serious disease; preserve functioning of society, including the protection of individuals who 

are relied upon to fight the pandemic; and reduce disproportionate burden on those with existing 

disparities. As part of this, the WG affirmed that consideration should be given to maximizing 

benefits and minimizing harms, utilizing a transparent and fair process, assuring the just and fair 

stewardship of vaccines, and removing barriers to vaccination. 

The discussions guided by these frameworks led to a proposed general approach for

prioritization primarily to help with operational planning for vaccine implementation. The WG 

recognizes that this is an iterative process with priority groups to be refined as more information 

becomes available. The WG’s assessment is that healthcare and other essential workers and 

high-risk populations should be vaccinated first, followed by general population. In this proposed 

highest priority group, persons at increased risk for severe COVID-19 include adults aged ≥65

years, long term care facility (LTCF) residents, and persons with high-risk medical conditions. 

Among the initial target group, the WG proposes that a subset of critical healthcare and other 

workers should receive the initial doses. This includes the highest risk medical, national 

security, and other essential workers in order to protect the healthcare infrastructure and other 

critical societal functions. Given the large population size of the remaining groups, further tiering 

of target groups may be necessary based on vaccine supply and program planning needs. 

There are several remaining information gaps in certain population subgroups, including the risk 

of disease and severe outcomes, vaccine safety and efficacy, and transmission dynamics and 

level of population immunity. These additional data would be helpful to inform prioritization, 

though decisions may need to be made in the setting of unknowns in order to proceed with 

vaccine implementation planning and avoid delays once a vaccine is available.

In summary, identifying priority groups for initial COVID-19 vaccination prior to the approval of a

vaccine is critical for implementation planning. Lessons learned from the H1N1 influenza 

pandemic highlight importance of national guidance while allowing for state and local flexibility in 

implementation. The WG proposes priority groups for COVID-19 vaccination, including 

healthcare and other essential workers and persons at increased risk for severe disease. The 

prioritization will need to be refined as more information becomes available.

ACIP’s feedback was requested on the following questions regarding key population groups in 

order to support vaccine program planning:

 Does ACIP agree that critical healthcare and other workers should be in Tier 1 for 

vaccination?

 What are ACIP’s thoughts on prioritization for residents of LTCF, other congregate settings, 

children, and pregnant women?
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 How should racial and ethnic groups at high risk for severe COVID-19 be prioritized? Should 

race and ethnicity be a criterion for vaccine prioritization?

 Are there other data that ACIP would like to review to help inform prioritization?

In terms of next steps, the proposed priority groups to be further refined based on ACIP’s

feedback with a goal to have a completed draft prioritization framework at the next meeting.

Discussion Points

Dr. Ault noted that ACIP went through the process shown on Slide 5 specific to pregnancy with 

the 2009 influenza pandemic. There is plenty of good information, white papers, and experience 

from that exercise that would help with this process as well.

Dr. Hunter expressed concern that it may be necessary to distribute and administer vaccines for 

COVID within a narrow window of time, and wondered whether it is necessary to achieve 

enough immunity and enough people simultaneously in order to slow or end the pandemic. 

Immunity after COVID illness appears to be short-lived, which raises concern that the peak 

immunity also may be short-lived. Therefore, it may be necessary to vaccinate everybody at the 

same time to achieve herd immunity. He asked whether these concerns had been discussed 

within the WG.

Dr. Mbaeyi indicated that the WG has discussed issues pertaining to transmission and levels of 

immunity. The plan is to address this further as the WG meetings progress and during a future 

ACIP meeting. There are still some data the WG would like to review to help inform some of 

those decisions. At this time, the WG feels that the subsets of HCP and other essential workers 

should be the first to be vaccinated.

Dr. Szilagyi said he thought the reason they were not seeing hands raised is because this is so 

tough. He does think there will be a need for prioritization and appreciated mention of “critical 

healthcare workers.” He is a healthcare worker but would not consider himself to be a critical 

healthcare worker, so he thinks there will need to be differentiation even in Tier 1. He thinks 

they have to follow the data as much as possible for LTCF and Native Americans, for whom the 

data are profound. The data about children not being affected as much by the coronavirus and 

being largely asymptomatic are also pretty strong. He is struggling about what to do with race 

and ethnicity. It is clear that African Americans, Native Americans, and Latino populations are at 

higher risk and that a large part of that has to do with underlying conditions and access barriers. 

There should be a focus on underlying conditions, eliminating barriers, and inversely increase 

the level of intervention for people who have barriers to access (low-income populations, people 

who have difficulty reaching healthcare). Interventions should be optimized for those groups. He 

is still struggling with which tier to put that last group in.

Dr. Romero commented that if they fail to address the issue of racial and ethnic groups as a 

high risk in prioritization, whatever comes out of ACIP will be looked at very suspiciously and 

with reservation. Dr. Szilagyi suggested improving healthcare access to these groups, but this 

will not address the problems that exist now. These individuals already have significant 

comorbid conditions that will not be reversed in a matter of months. Therefore, this issue must 
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be dealt with at this time with the information available. These groups need to be moved to the 

forefront in his opinion, which can be further discussed within the WG.

Dr. Sanchez agreed that this is a very difficult process and that there are racial groups that are 

at highest risk. Mandatory vaccination of HCP as is done with influenza is also going to shift 

numbers. There has not been success with prioritization of groups with influenza vaccination. 

He recalled that when high risk groups were targeted initially with influenza vaccines, children 

who were seen in clinics were not in high risk groups and were expected to return to get 

vaccinated. He thinks they will have to be accepting of some lower risk groups as vaccine 

supply becomes more abundant, because they may end up not being able to provide a sufficient 

immunity length to curb the pandemic. Strict prioritization could result in many high-risk people 

not wanting to get the vaccine for whatever reason. He has seen estimates in some surveys of 

50% to 60% for a potential vaccine.

Dr. Mbaeyi clarified that CDC does not make mandates for vaccination, including for HCP. This 

typically would be determined within a hospital system. Any sort of recommendation made by 

ACIP would not imply a mandate for vaccination.

Dr. Poehling said she also was struggling with race and ethnicity because of the numbers they 

saw earlier. She lives in a state where there are multiple poultry factories with profound impact, 

which also overlaps with race/ethnicity. She asked whether the “other” category would include 

poultry workers and other areas that have been particular hotspots.

Dr. Mbaeyi said that what the WG had discussed thus far was identifying not only critical 

healthcare, but also essential workers. A number of potential groups could be considered in the 

highest tier. The next steps would be to drill down to identify which particular groups would be 

the most critical to go in the first tier, given that there are many people who provide essential 

and helpful services, understanding that the others would follow in subsequent groups for 

prioritization. They welcome any thoughts on that as well.

Dr. Frey emphasized the importance of putting the topic of racial/ethnic groups squarely on the 

table, which appeared to be what most people preferred. It is very important to put the groups 

into a high tier—maybe not the whole population, but parts of those populations such as urban 

poor and working poor. Disadvantaged populations have a lot of comorbidities because they do 

not have access to healthcare because they cannot afford it, but they also are living in crowded 

conditions compared to other people in which there are multiple family members living in small 

apartments for example. Also, the working poor have to work. They cannot take off like some 

people do because they have to feed their families, so they also are disadvantaged in that way. 

She is a big proponent of prioritizing some of these groups in some areas, certainly to address 

people living in urban areas in crowded conditions.

Dr. Atmar asked whether “other congregate settings” includes prisons. Regarding one of the 

decisions the WG made about including or not excluding from the prioritization those groups 

who have historically had poor immune responses but might not be included in vaccination 

studies. Certainly, the LTCF and nursing home residents represent populations that are at 

extreme risk based on data that have been presented. They also are populations who have 

been less well-protected against influenza. It is important to vaccinate the HCP taking care of 
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the residents or the personnel working in the facility to provide protection. From his 

understanding, this population is not being targeted for active immunization, but instead would 

be targeted for passive immunization, at least in a lot of initial studies. As an at-risk group, he 

wondered whether they should be targeted for vaccination studies as well. He said that while he 

understood the rationale for why that might not happen initially, he was conflicted by recognizing 

that they are a group at particular risk and also that they may be a group less likely to benefit 

from vaccine when there are other groups that might benefit to a larger degree. He wondered 

what the WG thought about those questions.

Dr. Mbaeyi clarified that “other congregate settings” could include prisons, homeless shelters, or 

other areas where people are in close quarters with one another where there have been 

outbreaks. The WG has discussed LTCF residents at length and recognizes that they are at 

extremely high risk, but currently there is not any evidence either way regarding their levels of 

protection in terms of efficacy. Therefore, the WG in general felt that they should continue to be 

considered a high priority group and if data emerge that suggest otherwise, this can be reevaluated continuously. Given their high-risk and high death rates, they continue to be viewed 

as a high priority group. In addition, the WG discussed the workers and HCP at these facilities 

and also felt that they should be considered highly for vaccination given their role in taking care 

of this vulnerable population. When there are data on vaccines, these decisions can be 

reassessed.

Dr. Atmar asked whether this also could be reassessed if passive immunization strategies are 

effective.

Dr. Mbaeyi indicated that this is not something the WG is evaluating.

Dr. Cohn reminded everyone that these are still very early discussions at ACIP and among the 

WG. The reason they wanted to have this public meeting was to acquire ACIP’s input on where 

they should go with some of these discussions. These things will evolve as they get more data 

and continue to think these issues through, and they will be discussed again at future meetings.

Dr. Bernstein agreed about how difficult this discussion is. He expressed interest in knowing 

how the 5 tiers were established. It seemed to him that there was a huge overlap of the 

populations within each tier and also between the tiers. He also wondered what role the success 

of vaccine development would play in perhaps shuffling the different populations into different 

tiers.

Dr. Mbaeyi indicated that this was derived from the 2009 pandemic influenza guidance. The 

tiers were developed based on the recognition that there would be a need for not only vaccine 

supply reasons, but also for vaccine implementation reasons to have tiers of priority groups 

identified based on their population size, risks, et cetera and recognizing that it would be 

unlikely that the entire population could be vaccinated at the same time. That was the genesis 

behind the proposed tier structure for COVID-19. If an adult HCP is in Tier 1, they would not 

also fall into another tier where healthy adults are addressed. There should not be a lot of 

overlapping populations between the tier groups.
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Dr. Messonnier added that the 5 tiers do not represent a magic number. This last came out in 

2018. The initial process to develop this took multiple years and involved a lot of stakeholder 

and public outreach. Because so much groundwork already had been done, the WG began with 

the same framing knowing that unfortunately they do not have 2 years to figure it out. This is not 

meant to hold ACIP to 5 tiers. Of course, when more data become available on the different 

vaccines, the tiers will be adjusted. If the first vaccine available is less immunogenic in older 

adults, that would change the tiering. The issue now is that they need to start planning and 

some of these early considerations have significant impact on operational planning for the fall. 

They recognize that they are asking ACIP to do an insurmountable task in the absence of 

sufficient data. Yet, this is the situation in which CDC finds itself. As always when faced with 

tasks that seem insurmountable, CDC seeks advice from ACIP. CDC recognizes that ACIP 

does not have perfect information, yet the agency has never needed ACIP’s guidance more 

than now.

Dr. Szilagyi asked whether the WG considered combining underlying conditions 

(cardiopulmonary, obesity, diabetes, access problems) as an example of a group of patients.

Dr. Mbaeyi referred to Slide 17, indicating that the WG did place persons with underlying 

conditions in the priority group to be vaccinated. That would include the people to whom Dr. 

Szilagyi referred.

Dr. Cohn clarified that the slide that was up for discussion was to address some additional 

groups who were not defined as specifically in the proposed priority groups.

In thinking about return to school, Ms. McNally asked whether there had been discussions about 

teachers.

Dr. Mbaeyi indicated that the WG has been discussing teachers. The WG views the next task to 

drill down to be more specific to define certain types of workers. Teachers have been discussed 

and the WG wants feedback on that as well.

Dr. Poehling pointed out that closure of schools has had profound impact on some adults 

throughout communities, so they probably should talk about teachers and children. The 

negative impacts on their educational attainment are becoming quite clear.

Dr. Hunter wondered whether they were looking at the groups in the wrong way. As a local 

public health representative, he was thinking that the venue and mechanism of getting the 

vaccine out as quickly as possible to as many people as possible may be more about targeting 

particular venues, areas, and groups of clinics like Federally Qualified Health Centers (FQHCs). 

This is definitely not the time for shared clinical decision-making between the patient and 

physician. Maybe it should be about whomever wants it gets it now in order to get as many of 

the shots out as quickly as possible. If they are setting it up to be an individual patient-by-patient 

decision between a clinician or healthcare system trying to set up a decision tree that each 

clinicians or clinic has to decide, that might be the wrong way to do it.
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Dr. Messonnier stressed that what Dr. Hunter just said is the key point. CDC’s plans to 

operationalize this are to target groups rather than individuals. She can visualize approaches for 

the essential workers and others in the Tier 1 groups to easily access them by going through the 

places they work, such as hospitals and poultry plants, to take the vaccines directly to them. 

They still will leave room for individual decision-making for folks who are not in these higher risk 

groups. They do think that FQHCs represent a key group, which CDC is working with now in 

terms of influenza vaccination. If ACIP says they want CDC to prioritize minority groups, they 

would look to see where they could best access those groups. That might be partly through 

FQHCs, beauty salons, or other places where people tend to congregate. One of the reasons 

CDC wants this discussion early about how ACIP recommends the agency prioritizes is 

because then they want to turn it into operational planning with state and local health 

departments. They learned from H1N1 not to over-engineer it, but until ACIP articulates to CDC 

how the agency should prioritize, they cannot get to the next step of microplanning in each 

location. It is not just a top-down federal strategy. It is going to take the entire immunization 

infrastructure, including state and local health and local partners, to determine how to access 

priority groups.

Dr. Talbot thought it would be essential to know how the virus is transmitted and who is 

transmitting it. They learned a lot from pneumococcus in that is spread by children in whom very 

good vaccine responses are achieved.

Dr. Oliver indicated that the Epidemiology Task Force group at CDC has been working on some 

household transmission studies in some of the early outbreak areas throughout the country. As 

those data come in, they are helping inform to some extent who the primary index case and 

secondary case were in the household. Hopefully, they will be able to present those data to 

ACIP soon.

Dr. Frey suggested that it would be interesting to understand estimates for availability of 

product, production capabilities of the manufacturers, and in what countries products will be 

available from those manufacturers. Consideration may have to be given to different models 

based on the number of vaccines there actually are.

Dr. Messonnier agreed and indicated that information becomes available, they will be 

transmitting it. She stressed that it is likely that some of these discussions they are having will 

be in the absence of complete data. That being said, they have a general sense as always that 

they need to be flexible. In vaccine development, there are many potential areas where things 

can turn out differently than expected. The goal is to have enough vaccine by next year to 

vaccinate everyone in the American public. They are not talking about an end goal of 1 million 

doses of vaccine a year. They are talking about a goal of enough vaccine for everybody. 

However, it is unknown when those quantities of vaccine will be available or which vaccines it 

will be.

Dr. Romero pointed out that having increased numbers of vaccines and different products also 

adds another layer of complexity. What if a vaccine is efficacious but is not as efficacious as all 

of the vaccines? That also falls into the prioritization issue of the vaccine. It is great to have 

more vaccine, but they probably are not all going to be the same with regard to efficacy and 
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protection. That is going to lead them to having to think about more issues in terms of 

prioritization.

Dr. Bernstein noted that in the initial influenza recommendations, they were earmarking highrisk people and then over time transitioned to universal recommendations. He wondered with 

such a large percentage of the population being susceptible if they might need to be considering 

the family unit or something along those lines. It would be difficult to separate a mother/infant 

dyad. Taking a group approach, it was not clear how to separate that within families in a local 

community.

Dr. Frey asked how much discussion there has been around efficacy of these vaccines, what is 

going to be considered acceptable, and if it will be similar to influenza vaccine that has a rather 

limited efficacy compared to many other vaccines.

Dr. Messonnier said she thought it was premature to try to guess. The likelihood is that this 

vaccine will first be used under an EUA, but that is still under discussion. Like any vaccine, once 

it is licensed, the process will continue to be that CDC will come to ACIP for recommendations. 

It was a good question to ask whether ACIP would be routinely recommending a vaccine that 

has an efficacy more similar to influenza. There are a variety of groups at CDC and in the US 

government broadly who are working on modeling. They certainly can request a presentation to 

the WG to provide some input into the potential impact of a vaccine at different effectiveness 

levels so that ACIP can get a head start on thinking through how that might impact its 

recommendations.

Dr. Foster (APhA) emphasized pharmacy’s major role in the distribution process of vaccines. 

One of the problems they had with the H1N1 process was that pharmacy was at a low priority 

for receiving the vaccines. One advantage is that they are distributed through almost every 

area, plus a lot of pharmacies have the ability to put a sign out front saying, “Get your vaccine 

here.” He requested that they keep in mind that sooner distribution to pharmacies may be 

beneficial to getting the vaccine distributed.

Dr. Mbaeyi recognized that being more inclusive of pharmacies was a major lesson learned 

from H1N1.

Dr. Drees (SHAE) indicated that SHAE is very interested in how this vaccine would be 

distributed among HCP. SHAE has endorsed a policy for mandatory influenza vaccination for 

HCP and was in the process of expanding that to all vaccines recommended for HCP, though 

that got sidelined with COVID-19. Obviously, it would still be a local decision. Even within the 

smallest group of critical HCP, there will still need to be some prioritization. One struggle with 

H1N1 vaccine regarded whether to prioritize people who were most likely to come in contact 

with the disease versus those who were most likely to have severe consequences of the 

disease or some combination of the two. She assumed that being vaccinated would not change 

the PPE recommendations in any way. They are seeing the lowest infection rates on their 

COVID units because those personnel know that they are always dealing with COVID patients. 

The people not dealing with COVID all of the time are the ones getting infected. It just adds 

more complexity.
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Ms. Hayes (ACNM) pointed out that in the entire conversation about vulnerable populations, 

they have to remember how many people are uninsured in people of color communities. They 

also must talk about who will be subsidizing this vaccine when it becomes available, because 

the vast majority of people who are uninsured are not going to want to pay out of pocket for it.

Work Group Considerations and Next Steps

Kathleen Dooling, MD MPH

Co-Lead ACIP COVID-19 Vaccine Work Group

Medical Officer, National Center for Immunization and Respiratory Diseases

Centers for Disease Control and Prevention

Dr. Dooling summarized the considerations and discussions of the ACIP COVID-19 Vaccine 

WG, as well as the intended next steps. The WG looks forward to ACIP’s feedback in order to 

achieve its work plan. The WG’s proposed objectives of the COVID-19 Vaccine Program are to: 

1) ensure the safety and effectiveness of COVID-19 vaccines; 2) reduce transmission, 

morbidity, and mortality of COVID-19 disease; 3) help minimize disruption to society and the 

economy, including maintaining healthcare capacity; and 4) ensure equity in vaccine allocation 

and distribution. 

The WG is engaged with experts in several disciplines to ground its discussions in the best 

available science. There are a number of knowns and key unknowns that will be important for 

vaccine policy. With regard to COVID-19 immune response, it is known that most people with 

SARS-CoV-2 develop antibodies, usually within 2 weeks, and most patients mount neutralizing 

antibody responses. Key unknowns about the immune response regard the duration of immunity

following SARS-CoV-2 infection, whether neutralizing antibodies protect against viral infection, 

and whether there are immunologic correlates of protection. 

In terms of epidemiology in the US, it is known that there are multiple populations with evidence 

of high risk of COVID-19 disease or severity. Those include occupationally defined categories, 

such as healthcare or agricultural workers; people who have individual characteristics that put 

them at higher risk, such as older age or underlying medical conditions; inequities and social 

determinants of health (SDOH) resulting in disproportionate impact on people belonging to 

American Indian, Black, or Hispanic race/ethnic groups; and people living in congregate 

settings, such as those in long-term care, correctional facilities, and the homeless. People in 

congregate settings have been especially hard hit, and dramatically so when the individuals 

living within them are already at high risk. Outbreaks in long-term care, correctional facilities, 

and homeless shelters have demonstrated high attack rates of disease that are frequently 

accompanied with tragic case fatality rates.

Some of the key epidemiologic unknowns important for vaccine policy pertain to the proportion 

of viral transmission contributed by children; the risk of disease and severity in pregnant women; 

the true incidence of multisystem inflammatory syndrome in children (MIS-C) and the long-term

sequalae; and the current level of population immunity and heterogeneity by factors such as

geography, occupation, race, and ethnicity. 
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Of course, COVID-19 vaccine policy will depend on detailed understanding of the vaccines that 

are proven safe and effective in clinical trials. Multiple platforms are being utilized to develop 

COVID-19 vaccines. Multiple approaches increase the chances of developing safe and effective 

vaccines to meet national and global needs. Vaccines must meet stringent safety standards in 

clinical trials. Otherwise, they will not be used in the population. Some of the key unknowns 

regarding COVID-19 vaccines that will be necessary for policy include vaccine characteristics

such as number of doses, route of administration, and storage temperatures required. It is also 

necessary to understand vaccine performance. For example, it is important to understand 

immunogenicity and efficacy by age and risk groups. It also would be helpful to know the 

interval from vaccination to protection. To understand the role of a future vaccine in controlling 

the pandemic, it is necessary to know the vaccine’s effect on acquisition of infection and

transmission. It also is necessary to understand any AE profile by age and risk groups. Finally, it 

is important to know the FDA approved populations. 

To elaborate on that process, Dr. Dooling provided an overview of the path of a vaccine from 

clinical development to recommendation. The purpose of clinical development is to generate 

safety, immunogenicity, and efficacy data. Enhancements facilitated through OWS, which have 

been introduced to achieve the goal of a safe and effective COVID-19 vaccine, include close 

coordination and cooperation within government (OWS, DHHS, CDC, NIH, ASPR, and DoD), as 

well as the manufacture of vaccine during this early period which could save months if a vaccine 

is approved.

FDA’s role is to apply stringent requirements to ensure the safety, purity, and potency of 

licensed vaccines where potency is understood to mean effectiveness. In specific 

circumstances, FDA may grant EUA for the use of an unlicensed vaccine or for the use of a 

licensed vaccine for an indication that has not yet been approved for labeling, such as the case 

of anthrax vaccine adsorbed (AVA) that received EUA for post-exposure prophylaxis (PEP). 

Additionally, it is possible to make unlicensed vaccines available outside of clinical trials through 

Expanded Access under Investigational New Drug (IND) such as in the case of MenB vaccine

used to address college outbreaks of meningitis.

ACIP reviews the evidence generated and using the EtR, provides advice and guidance to CDC 

and the Secretary of DHHS on the optimal way to prevent vaccine-preventable disease in a 

civilian population. Once a CDC recommendation is in place, it becomes the standard of clinical 

practice for vaccination in the US and post-approval monitoring is initiated. This is a critical next 

step in the integrity of the national vaccine program and provides important checks on the safety 

and effectiveness of the vaccines used in the real-world. These data are fed back to FDA, CDC, 

and ACIP.

The EtR is the tool used by ACIP to provide transparency and consistency when developing 

evidenced-based recommendations. The framework examines evidence in multiple domains, as 

well as the uncertainty of that evidence to weigh whether or not a vaccine should be 

recommended and to whom. The first domain asks whether the disease is of public health 

importance. The WG has achieved consensus that the morbidity, mortality, and societal 

disruption caused by COVID-19 is of extreme public health importance. Next, the framework 

focuses on the expected benefits and possible harms of the vaccine. The WG will focus more 

on that domain as data become available. The next domains pertain to values, acceptability, 
Advisory Committee on Immunization Practices (ACIP) Summary Report June 24, 2020

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and feasibility of a vaccine policy recommendation. Through published evidence and community 

engagement, the WG will examine if the target populations value COVID-19 vaccination and the 

expected benefits therein. Separate but related the WG will assess whether the vaccine is 

acceptable to key stakeholders or if there are barriers to acceptability, such as uncertainty or 

lack of trust. Importantly, feasibility of implementing the program is assessed. The COVID-19 

vaccine program will undoubtedly involve unprecedented creativity and innovation in 

implementation. The feasibility must be considered at every step.

The ACIP COVID-19 Vaccine WG developed several guiding principles for the COVID-19 

vaccine program that have broad support among WG members. First, safety is paramount. 

Vaccine safety standards will not be compromised in efforts to accelerate COVID-19 vaccine 

development. The ACIP COVID-19 Vaccine WG supports inclusive clinical trials. Study 

participants should reflect groups at risk for COVID-19 to ensure that safety and efficacy data 

are generalizable. The WG values efficient distribution. During a pandemic, efficient, 

expeditious, and equitable distribution and administration of approved vaccine is critical. Finally, 

the WG supports flexibility. Within national guidelines, state and local jurisdictions should have

flexibility to administer vaccine based on local epidemiology and demand. 

The next steps for the ACIP COVID-19 Vaccine WG are to: 1) define the critical and important 

outcomes; that is, the benefits and risks that will feed into the EtR framework; 2) review clinical 

trial data for candidate vaccines, as it becomes available; 3) advance the understanding of 

safety issues with each vaccine platform and safety studies in Phases III & IV; 4) further refine 

Tier Groups for allocation of early vaccine, based on ACIP feedback; and 5) review proposed 

implementation strategies. 

In closing, Dr. Dooling posed the following questions for ACIP’s consideration and feedback:

 Do you agree with the proposed guiding principles?

 Do you agree with the next steps?

 What topics would you like to see presented at the next ACIP meeting?

Discussion Points

Ms. Bahta observed that the guiding principles seemed to match and support a lot of the 

comments made throughout the day. 

Dr. Hunter wondered whether there is a way to present modeling data about his concern that if

everyone is not vaccinated in a narrow window of time, there will be people with declining 

immunity who become re-susceptible to some degree or not. This sounds very difficult to model, 

but if there is any way to provide some data about that in the future it would be helpful.

Dr. Dooling said she thought the impetus behind the question that vaccine should be distributed 

expeditiously was captured in the guiding principles. The WG can take the specific question 

about modeling of the potential to be re-infected following vaccination to the modeling team. The 

WG eventually will present modeling results to ACIP and will add that to the list of questions.
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Centers for Disease Control and Prevention (CDC)

Dr. Messonnier said she thought it was incomplete to talk about the impact of COVID-19 without 

at least acknowledging the impact of COVID-19 on global immunization. Global immunization 

activities have indeed become challenging during the COVID-19 outbreak similar to what is 

occurring in the US. There are concerns that millions of people globally could miss routine 

immunizations this year due to the COVID-19 response. GAVI (Global Alliance for Vaccines and 

Immunisation; The Vaccine Alliance) has estimated that at least 13.5 million people will miss 

their routine immunizations. HCP and other health resources have been diverted to the COVID19 response, leaving immunization programs under-staffed. Parents are reluctant to take their 

children to healthcare clinics. Vaccines may not always be available. For example, global polio 

vaccine distribution has been impacted by reductions in air transport. CDC has been working 

with the United Nations Children’s Fund (UNICEF) and the World Health Organization (WHO) to 

assess the reduction in overall immunization in polio vaccination caused by the pandemic. WHO 

has issued interim guidance to help countries continue to plan and catch up with their routine 

immunization once the COVID-19 crisis eases. It is essential to maintain a global focus on 

routine immunization to prevent vaccine-preventable disease outbreaks and to help ensure the 

delivery of a COVID-19 vaccine once one becomes available.

Dr. Frank Whitlatch

Immunization Services Division

National Center for Immunization and Respiratory Diseases

Centers for Disease Control and Prevention

During this session, Dr. Whitlatch presented an update on the HepB vaccines supply and 

discontinuation of ZOSTAVAX®. 

Merck will be returning to the US market the week of July 20, 2020 for adult and dialysis 

formulations of RECOMBIVAX HB®. Merck will have sufficient supply to cover its historical 

demand for both vaccines. Both formulations will be available in vial presentation only. 

Effective July 1, 2020, Merck no longer will sell ZOSTAVAX® in the US. Merck does not have a 

specific date as to when the supply of ZOSTAVAX® will be depleted. All remaining product has 

an expiry date of no later than November 2020. Merck communicated this information directly to 

their customers in early June 2020.

As a reminder, CDC has a vaccine supply page that is kept updated in sync with all of the 

updates made during ACIP meetings. The Vaccine Supply/Shortage Webpage can be found at:

https://www.cdc.gov/vaccines/hcp/clinical-resources/shortages.html.

Agency Updates

Vaccine Supply
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Upon reviewing the foregoing version of the June 24, 2020 ACIP meeting minutes, Dr. Jose 

Romero, ACIP Chair, certified that to the best of his knowledge, they are accurate and 

complete. His original, signed certification is on file with the Management Analysis and Services 

Office (MASO) of CDC.

Certification
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Department of Health and Human Services 

Centers for Disease Control and Prevention 

Advisory Committee on Immunization Practices 

July 1, 2019 – June 30, 2020 

 

CHAIR 

ROMERO, José R., MD, FAAP 

Professor of Pediatrics 

Horace C. Cabe Endowed Chair in Infectious Diseases Director, 

Pediatric Infectious Diseases Section 

University of Arkansas for Medical Sciences and Arkansas Children's Hospital 

Director, Clinical Trials Research 

Arkansas Children's Hospital Research Institute 

Little Rock, AR 

Term: 10/30/2018-06/30/2021 

 

EXECUTIVE SECRETARY

COHN, Amanda, MD 

Senior Advisor for Vaccines 

National Center for Immunization and Respiratory Diseases 

Centers for Disease Control and Prevention 

Atlanta, GA 

 

MEMBERS 

ATMAR, Robert L., MD 

John S. Dunn Clinical Research Professor in Infectious Diseases 

Departments of Medicine and Molecular Virology & Microbiology 

Baylor College of Medicine 

Chief, Infectious Diseases Service 

Ben Taub General Hospital, Harris Health System

Houston, TX 

Term: 7/1/2016 – 6/30/2020 

AULT, Kevin A., MD, FACOG, FIDSA 

Professor and Division Director 

Department of Obstetrics and Gynecology 

University of Kansas Medical Center

Kansas City, KS 

Term: 10/26/2018 – 6/30/2022 

 

ACIP Membership Roster
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BAHTA, Lynn, RN, MPH, CPH 

Immunization Program Clinical Consultant 

Infectious Disease, Epidemiology, Prevention & Control Division 

Minnesota Department of Health 

Saint Paul, Minnesota 

Term: 7/1/2019 – 6/30/2023 

 

BELL, Beth P., MD, MPH 

Clinical Professor 

Department of Global Health, School of Public Health 

University of Washington 

Seattle, WA 

Term: 7/1/2019 – 6/30/2023 

BERNSTEIN, Henry, DO, MHCM, FAAP 

Professor of Pediatrics 

Zucker School of Medicine at Hofstra/Northwell 

Cohen Children’s Medical Center 

New Hyde Park, NY 

Term: 11/27/2017-06/30/2021 

 

FREY, Sharon E., M.D. 

Professor and Associate Director of Clinical Research 

Clinical Director, Center for Vaccine Development 

Division of Infectious Diseases, Allergy and Immunology 

Saint Louis University Medical School 

Saint Louis, MO 

Term: 11/27/2017-06/30/2021 

 

HUNTER, Paul, MD 

Associate Professor of Family Medicine and Community Health 

University of Wisconsin School of Medicine and Public Health 

Associate Medical Director 

City of Milwaukee Health Department 

Milwaukee, WI 

Term: 7/1/2016 – 6/30/2020 

 

LEE, Grace M., MD, MPH 

Associate Chief Medical Officer for Practice Innovation 

Lucile Packard Children’s Hospital 

Professor of Pediatrics, Stanford University School of Medicine 

Stanford, CA 

Term: 7/1/2016 – 6/30/2020 
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MCNALLY, Veronica V., JD 

President and CEO 

Franny Strong Foundation 

West Bloomfield, Michigan 

Term: 10/31/2018 – 6/30/2022 

 

POEHLING, Katherine A., MD, MPH 

Professor of Pediatrics and Epidemiology and Prevention Director, 

Pediatric Population Health 

Department of Pediatrics 

Wake Forest School of Medicine 

Winston-Salem, NC 

Term: 7/1/2019 – 6/30/2023 

SÁNCHEZ, Pablo J., M.D.

Professor of Pediatrics 

The Ohio State University – Nationwide Children’s Hospital 

Divisions of Neonatal-Perinatal Medicine and Pediatric Infectious Diseases 

Director, Clinical & Translational Research (Neonatology) 

Center for Perinatal Research 

The Research Institute at Nationwide Children's Hospital 

Columbus, Ohio

Term: 7/1/2019 – 6/30/2023 

 

SZILAGYI, Peter, MD, MPH 

Professor of Pediatrics 

Executive Vice-Chair and Vice-Chair for Research 

Department of Pediatrics 

University of California, Los Angeles (UCLA) 

Los Angeles, California 

Term: 7/1/2016 – 6/30/2020 

 

TALBOT, Helen Keipp, MD 

Associate Professor of Medicine 

Vanderbilt University

Nashville, TN 

Term: 10/29/2018 – 6/30/2022 
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EX OFFICIO MEMBERS 

Centers for Medicare and Medicaid Services (CMS) 

HANCE, Mary Beth 

Senior Policy Advisor 

Division of Quality, Evaluations and Health Outcomes 

Children and Adults Health Programs Group 

Center for Medicaid, CHIP and Survey & Certification 

Centers for Medicare and Medicaid Services 

Baltimore, MD 

 

Department of Defense (DoD) 

SCHUMACHER, Bryan, MD

Department of Defense Liaison

Centers for Disease Control and Prevention

Atlanta, GA

Department of Veterans Affairs (DVA) 

KIM, Jane A., MD, MPH 

Deputy Chief Consultant for Preventive Medicine 

Office of Patient Care Services 

National Center for Health Promotion and Disease Prevention 

Durham, North Carolina 

 

Food and Drug Administration (FDA) 

FINK, Doran, MD, PhD 

Deputy Director, Clinical, Division of Vaccines and Related Products Applications 

Office of Vaccines Research and Review 

Center for Biologics Evaluation and Research 

Food and Drug Administration Silver 

Spring, MD 

 

Health Resources and Services Administration (HRSA) 

RUBIN, Mary, MD 

Chief Medical Officer 

Division of Injury Compensation Programs 

Rockville, MD 

Indian Health Service (IHS) 

WEISER, Thomas, MD, MPH 

Medical Epidemiologist 

Portland Area Indian Health Service 

Portland, OR 
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Office of Infectious Disease and HIV/AIDS Policy (OIDP) 

KIM, David, MD CAPT, 

US Public Health Service Director Division of Vaccines 

Washington, DC 

National Institutes of Health (NIH) 

BEIGEL, John, M.D. 

Associate Director for Clinical Research 

Division of Microbiology and Infectious Diseases 

National Institute of Allergy and Infectious Diseases (NIAID) Bethesda, MD 

 

LIAISON REPRESENTATIVES 

American Academy of Family Physicians (AAFP) 

ROCKWELL, Pamela G, DO 

Associate Professor, Department of Family Medicine, 

University of Michigan Medical School 

Medical Director, Dominos Farms Family Medicine Ann 

Arbor, MI 

 

American Academy of Pediatrics (AAP) 

MALDONADO, Yvonne, MD 

Senior Associate Dean for Faculty Development and Diversity 

Professor of Pediatrics and Health Research and Policy 

Chief, Division of Pediatric Infectious Diseases 

Stanford University School of Medicine 

Stanford, CA 

 

American Academy of Pediatrics (AAP) 

Red Book Editor 

KIMBERLIN, David, MD 

Professor of Pediatrics 

Division of Pediatric Infectious Diseases 

The University of Alabama at Birmingham School of Medicine

Birmingham, AL 

 

American Academy of Physician Assistants (AAPA) 

LÉGER, Marie-Michèle, MPH, PA-C Senior 

Director, Clinical and Health Affairs 

American Academy of Physician Assistants

Alexandria, VA 

American College Health Association (ACHA) 

CHAI, Thevy S, MD 

Director of Medical Services 

Campus Health Services 

University of North Carolina at Chapel Hill 

Chapel Hill, NC
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American College Health Association (ACHA) (alternate) 

MCMULLEN, Sharon, RN, MPH, FACHA 

Assistant Vice President of Student & Campus Life for Health and Wellbeing 

Cornell Health 

Ithaca, NY 

American College of Nurse Midwives (ACNM) 

HAYES, Carol E., CNM, MN, MPH Lead 

Clinician 

Clinical Quality Compliance and Management 

Planned Parenthood Southeast 

Atlanta, GA 

American College of Nurse Midwives (ACNM) (alternate) 

MEHARRY, Pamela M., PHD, CNM 

Midwifery Educator, Human Resources for Health 

In partnership with University of Rwanda and University of Illinois, Chicago 

American College of Obstetricians and Gynecologists (ACOG) 

ECKERT, Linda O., MD, FACOG 

Professor, Department of Obstetrics & Gynecology 

Adjunct Professor, Department of Global Health 

University of Washington 

Seattle, WA 

American College of Physicians (ACP) 

GOLDMAN, Jason M. MD, FACP 

Affiliate Assistant Professor of Clinical Biomedical Science, Florida Atlantic 

University, Boca Raton, Florida 

Private Practice 

Coral Springs, FL 

American Geriatrics Society (AGS) 

SCHMADER, Kenneth, MD 

Professor of Medicine-Geriatrics 

Geriatrics Division Chief 

Duke University and Durham VA Medical Centers

Durham, NC 

America’s Health Insurance Plans (AHIP) 

Vacant

American Immunization Registry Association (AIRA) 

COYLE, Rebecca, MSEd 

Executive Director, AIRA

Washington, DC 
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American Medical Association (AMA) 

FRYHOFER, Sandra Adamson, MD 

Adjunct Associate Professor of Medicine 

Emory University School of Medicine

Atlanta, GA 

 

American Nurses Association (ANA) 

RITTLE, Charles (Chad), DNP, MPH, RN 

Assistant Professor, Nursing Faculty 

Chatham University, School of Health Sciences

Pittsburgh, PA 

 

American Osteopathic Association (AOA) 

GROGG, Stanley E., DO 

Associate Dean/Professor of Pediatrics 

Oklahoma State University-Center for Health Sciences 

Tulsa, OK 

American Pharmacists Association (APhA) 

FOSTER, Stephan L., PharmD CAPT (Ret) 

U.S.P.H.S. 

Professor, College of Pharmacy 

University of Tennessee Health Sciences Center 

Memphis, TN 

Association of Immunization Managers (AIM) 

FINLEY, Christine, RN, MPH 

Immunization Program Manager 

Vermont Department of Health 

Burlington, VT 

 

Association for Prevention Teaching and Research (APTR) 

McKINNEY, W. Paul, MD 

Professor and Associate Dean 

University of Louisville School of Public Health and Information Sciences

Louisville, KY 

Association of State and Territorial Health Officials (ASTHO) 

SHAH, Nirav D, MD, JD

Director 

Maine Center for Disease Control and Prevention

Augusta, ME
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Biotechnology Industry Organization (BIO) 

ARTHUR, Phyllis A., MBA 

Senior Director, Vaccines, Immunotherapeutics and Diagnostics Policy 

Washington, DC

Council of State and Territorial Epidemiologists (CSTE) 

HAHN, Christine, MD State 

Epidemiologist 

Office of Epidemiology, Food Protection and Immunization Idaho 

Department of Health and Welfare

Boise, ID 

 

Council of State and Territorial Epidemiologists (CSTE) (alternate) 

LETT, Susan, MD, MPH 

Medical Director, Immunization Program 

Division of Epidemiology and Immunization 

Massachusetts Department of Public Health 

Boston, MA 

 

Canadian National Advisory Committee on Immunization (NACI) 

QUACH, Caroline, MD, MSc 

Pediatric Infectious Disease Specialist and Medical Microbiologist 

Medical Lead, Infection Prevention and Control Unit 

Medical Co-director – Laboratory Medicine, Optilab 

Montreal-CHUM 

Montreal, Québec, Canada 

 

Infectious Diseases Society of America (IDSA) 

BAKER, Carol J, MD 

Professor of Pediatrics 

Molecular Virology and Microbiology 

Baylor College of Medicine

Houston, TX 

 

National Association of County and City Health Officials (NACCHO) 

ZAHN, Matthew, MD 

Medical Director, Epidemiology 

Orange County Health Care Agency 

Santa Ana, CA 

 

National Association of County and City Health Officials (NACCHO) (alternate) 

DUCHIN, Jeffrey, MD 

Health Officer and Chief, Communicable Disease Epidemiology and Immunization Section 

Public Health - Seattle and King County 

Professor in Medicine, Division of Allergy and Infectious Diseases 

University of Washington School of Medicine and School of Public Health

Seattle, WA
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National Association of Pediatric Nurse Practitioners (NAPNAP) 

STINCHFIELD, Patricia A., RN, MS, CPNP 

Director, Infectious Disease/Immunology/Infection Control 

Children's Hospitals and Clinics of Minnesota

St. Paul, MN 

 

National Foundation for Infectious Diseases (NFID) 

SCHAFFNER, William, MD 

Chairman, Department of Preventive Medicine 

Vanderbilt University School of Medicine 

Nashville, TN 

National Foundation for Infectious Diseases (NFID) (alternate) 

DALTON, Marla, PE, CAE 

Executive Director & CEO 

National Foundation for Infectious Diseases (NFID) 

Bethesda, MD

National Medical Association (NMA) 

WHITLEY-WILLIAMS, Patricia, MD 

Professor and Chair 

University of Medicine and Dentistry of New Jersey 

Robert Wood Johnson Medical School 

New Brunswick, NJ 

 

Pediatric Infectious Diseases Society (PIDS) 

O’LEARY, Sean, MD, MPH 

Associate Professor of Pediatrics 

Pediatric Infectious Diseases 

General Academic Pediatrics 

Children’s Hospital Colorado 

University of Colorado School of Medicine 

 

Pediatric Infectious Diseases Society (PIDS) (alternate) 

SAWYER, Mark H, MD 

Professor of Clinical Pediatrics 

University of California, San Diego School of Medicine 

San Diego, CA 

 

Pharmaceutical Research and Manufacturers of America (PhRMA) 

ROBERTSON, Corey, MD, MPH 

Senior Director, US Medical, Sanofi Pasteur

Swiftwater, PA 
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Society for Adolescent Health and Medicine (SAHM) 

MIDDLEMAN, Amy B., MD, MSEd, MPH 

Professor of Pediatrics 

Chief, Section of Adolescent Medicine 

University of Oklahoma Health Sciences Center 

Oklahoma City, OK 

Society for Healthcare Epidemiology of America (SHEA) 

DREES, Marci, MD, MS 

Chief Infection Prevention Officer & Hospital Epidemiologist 

ChristianaCare 

Wilmington, DE 

Associate Professor of Medicine Sidney Kimmel Medical College at Thomas Jefferson 

University 

Philadelphia, PA